Primers - One better than Another?

[Wireman]

Hi, well I hear what you are saying about some brand being harder than some other brand. Looks like you have had more opportunity to try different types - I wouldn't know exactly what the differences are. I do believe that military rifles such as the AR/M16 platform do require a military style primer simply because the firing pin doinks the primer when the round is chambered. Eject an unfired round and confirm that there is a dent in those primers, and that has made me a believer in using the correct ammo with correct primers. Let's stick with pistol primers for now. I've never had any primer of any type fail to fire in my 1911's or .38spl revolvers. And, I maintain that all these shooters that complain and show photos of light strikes have a hardware problem, and not an ammo problem. If f.p. strikes are marginal, you will in fact get intermittant ignition. Yes, changing to a different ammo will in fact change the percentage of rounds that fire. That is a red herring. One guy at the range here pointed out how his reloads always fired in his Beretta 96, but factory ammo was about 50%. He therefore concluded that factory ammo was defective. That leads many to claim that their pistol "likes" a particular ammo, when in fact there are subtle differences between them. I have never seen a situation where a particular primer was to blame, at least in pistol rounds. The Beretta guy's real problem was that his chamber was reamed too deep and so the primer was actually too far away from his f.p. when using factory ammo. His reloads were seated a bit longer in OAL and thus fired reliably. That' s not a primer hardness problem, even though a softer primer would probably improved his % of rounds ignited. I offered to pay for a new Beretta barrel if a new one didn't fix the problem. A new barrel fixed the problem. Hardware.

 

[hdwhit]

Okay. I will commit reloading heresy here.

I have used every brand of primer (other than Federal, which I could never find) in both .223 Remington or 9mm Parabellum interchangeably (by brand).

In no case - over 40+ years - have I noticed an observable difference in the velocities or the condition of the brass from such firings.

While reloading orthodoxy says that primers can make a material difference in pressure and velocity, that has not been my experience with these two calibers. I cannot speak to others.

Still, there are hundreds of calibers, each with its own unique characteristics, so don't generalize from 223 and 9mm, but explore your own caliber and load according to published data.

 

[Slamfire]

I maintain that all these shooters that complain and show photos of light strikes have a hardware problem, and not an ammo problem. If f.p. strikes are marginal, you will in fact get intermittant ignition. Yes, changing to a different ammo will in fact change the percentage of rounds that fire. That is a red herring. One guy at the range here pointed out how his reloads always fired in his Beretta 96, but factory ammo was about 50%. He therefore concluded that factory ammo was defective. That leads many to claim that their pistol "likes" a particular ammo, when in fact there are subtle differences between them. I have never seen a situation where a particular primer was to blame, at least in pistol rounds. The Beretta guy's real problem was that his chamber was reamed too deep and so the primer was actually too far away from his f.p. when using factory ammo. His reloads were seated a bit longer in OAL and thus fired reliably. That' s not a primer hardness problem, even though a softer primer would probably improved his % of rounds ignited. I offered to pay for a new Beretta barrel if a new one didn't fix the problem. A new barrel fixed the problem. Hardware.

A good post. It is rare when a pistol does not come from the factory with sufficient energy to ignite factory primers. There have been such poorly designed mechanisms, because the designer and design team did not know primer sensitivity and the energy it took to ignite that average primer. An interesting one was Stoner. Stoner designed the M16 with a heavy firing pin,



and the thing passed initial testing and became the issue service rifle. Once the rifle got in service, rifles were slamfiring when rounds were chambered.


Icord report page 4560, Stoner giving testimony before a Congressional Committee:

Mr. Stoner. Well, yes, because I knew that the rifle was, you know, was going to be used by the armed service and I wanted to make sure that we had adequate background on it before we went into it. Because the history, and all the testing that was done with the IMR propellants. We had another thing that happened on the Marine Corps test that went with that. We had some inadvertent firings of the weapon due to the primer that we were using. We were using a commercial primer in that round which is relatively soft and sensitive, and the Marines, on their firing, on their known distance range, would single load the weapon. They would put a round in the chamber and then let the bolt go home by pushing the closing button on it or the bolt catch, and the inertia of the firing pin would fire the weapon sometimes this way.

It was a very low frequency, but it did happen. So, of course, they wanted something done about it, and the Army found out about this. There were a couple of solutions. Either desensitize the primer, make it out of a thick material, or lighten up the firing pin. Well, what I recommended was lightening up the firing pin because I didn’t see-if you desensitized the primer too much it could cause failures to fire in the field.

In other words, we wouldn’t have enough energy to fire the primer under all conditions. And I-in this technical data package they decreased the sensitivity of the primer at the same them they went in and put the ball propellant in. So these were two things I objected to with Mr. Vee.

Here again, I didn’t know what the effects would be because we didn’t have all this test data, I mean testing, behind us that we had on the other ammunition. While the design on the firing pin, to lighten it, which was subsequently done by Colt, was a relatively simple thing, and in my opinion, wouldn’t detract from the performance of the weapon any. As I say this weapon was tested for years and years and before this inadvertent firing ever come up and it come up because probably we had a batch of ammunition where the sensitivity level on these primers were on the low end, or, I should say, the high end of sensitivity, and also, the fact that there were firing the weapon in a way that they formerly didn’t before, which was single loading, when it was an automatic weapon.

Usually the weapon was loaded from the magazine and when the rounds were stripped out of the magazine like it was intended to be used, this slowed the bolt down enough that you didn’t have the impact velocity to cause an inadvertent firing.

There were actually two things that I took exception to on that. I didn’t sit in on the Board that came up with the ammunition specification. I wasn’t asked to. I am not in the ammunition business. But, I have a good deal of interest in the ammunition due to the fact- usually you can’t change the ammunition without causing a change in the performance of the weapon.

Stoner claims that the slamfires that occurred with his design, were due to the USMC not using the weapon properly, is in fact, pure hogwash and denial. It is unreasonable to design a rifle that can only be fed from the magazine. Stoner would have known the KD course of fire required loading the rifle single shot, both standing and prone slow fire. In this case, Stoner only knows about primer sensitivity as a conceptual basis. He does not know how much energy is required to ignite an average primer, and he does not know the kinetic energy of his firing pin. It turns out, if you study this, the kinetic energy of his early firing pin was always above the "none fire" limits of commercial primers. None fire is a very important safety criteria: no primer is supposed to ignite when hit by a firing pin whose kinetic energy is less than the "none fire" limit. Stoner's design, the primers were always being hit by a firing pin whose kinetic energy exceeded the "none fire" limit.

The Army could have put a spring under the firing pin, such as is done on the AR10 mechanism



but I am certain the Army did not want to add an extra part to their inventory, so they lightened the firing pin, and made a less sensitive primer. This is the top drawing for the #41 primer.



The less sensitive primer is something Stoner comments on, because he is worried about the energy output of his ignition system in extreme conditions. And this can be a real problem.

Now you will find mechanisms were the mainsprings have weakened over time, and they will misfire, particularly in cold weather. Been there! And, I see Bullseye pistol competitors who are using the weakest mainspring, and recoil spring, in their 1911's, to use the lightest recoiling loads. To day, no one has had problems with mainsprings, but they are always frustrated with their recoil springs causing failures to eject.

I recommend reading the section “Primer Sensitivity” in the book “Ammunition Making” by George Frost. When Mr Frost was in the business, revolvers were very common on the firing line. And to achieve the lightest double action pull, for timed fire and rapid fire, competitors used the lightest mainsprings they could find. Mr Frost comments that these shooters had to find the most sensitive primer lots for reliable ignition.

One thing that is a hardware issue is off center firing pin strikes.

Ideally, the firing pin should strike the primer right at the peak of the anvil.



The further offset the firing pin strike is from the anvil tip, the more energy it takes to have reliable ignition, and at some distance from center, the round won't fire.



I have a Ruger #1 rifle in 35 Whelen.


It misfired. The 35 Whelen has a small, slight shoulder, and that has caused misfires for me in other 35 Whelen's.



This is the only cartridge that I size the case for zero clearance in the chamber, the case shoulder is resting hard on the chamber shoulder, and there might be a slight crush up when I close the bolt. I was given advice to go for a 35 Brown Whelen, which has a sharper shoulder, but, I had not encountered misfires due to shoulder size, slope before. My Ruger misfired badly, even after switching to Federal LR primers, and installing a Wolff extra powder main spring. The thing was, the firing pin offset on the primer was bad, according to Ruger, 23 thousands from center. Ruger did fix the thing, by centering the breech and ignition is reliable.

But this is something that centerfire shooters should know about, and not accept sloppily made firearms from manufacturer's. If the firing pin is not striking the center of the primer, then, misfires can happen.

 

[Erich Duplantis]

My conclusion today is small rifle primers can be used in place of small pistol primers, if loading 38 special for revolvers.
I reloaded 22 ea. Winchester brass cartridges, charged with 4.8 gr of W231, using 158 grn Berry hollow point bullets, using small rifle primers(CCI). and 22 ea. Using the small pistol primers (CCI).
Loaded 4 revolvers with three of small rifle primers followed by three with the small pistol primers.
The four revolvers used were: EAA Windicator 4” barrel, S/W 686 plus with 3” barrel, S/W 686 with 4” barrel, and a S/W 642 snubby loaded with 2 and two of each (only hold five).
Shot plates at 25 feet. My experience was I found no difference in sound or feel between the two, all went off without a glitch.
During reloading the primers they (SRP) went right in with the right depth, no problem.
So being I have small rifle primers I will reload my 38 with these until I can find more Small pistol primers.
I feel safe and confident using these primers. You have to make your own conclusions.

 

[Fatelvis]

After 38 years of handloading, I see very little, if any accuracy difference between different brands of primers. Maybe my shooting or evaluating procedures aren't up to the level of the pros, but I don't sweat the little things anymore. Buy what's on sale (during normal times) and be happy!

 

[Fatelvis]

A good post. It is rare when a pistol does not come from the factory with sufficient energy to ignite factory primers. There have been such poorly designed mechanisms, because the designer and design team did not know primer sensitivity and the energy it took to ignite that average primer. An interesting one was Stoner. Stoner designed the M16 with a heavy firing pin,

View attachment 993184

and the thing passed initial testing and became the issue service rifle. Once the rifle got in service, rifles were slamfiring when rounds were chambered.


Icord report page 4560, Stoner giving testimony before a Congressional Committee:

Mr. Stoner. Well, yes, because I knew that the rifle was, you know, was going to be used by the armed service and I wanted to make sure that we had adequate background on it before we went into it. Because the history, and all the testing that was done with the IMR propellants. We had another thing that happened on the Marine Corps test that went with that. We had some inadvertent firings of the weapon due to the primer that we were using. We were using a commercial primer in that round which is relatively soft and sensitive, and the Marines, on their firing, on their known distance range, would single load the weapon. They would put a round in the chamber and then let the bolt go home by pushing the closing button on it or the bolt catch, and the inertia of the firing pin would fire the weapon sometimes this way.

It was a very low frequency, but it did happen. So, of course, they wanted something done about it, and the Army found out about this. There were a couple of solutions. Either desensitize the primer, make it out of a thick material, or lighten up the firing pin. Well, what I recommended was lightening up the firing pin because I didn’t see-if you desensitized the primer too much it could cause failures to fire in the field.

In other words, we wouldn’t have enough energy to fire the primer under all conditions. And I-in this technical data package they decreased the sensitivity of the primer at the same them they went in and put the ball propellant in. So these were two things I objected to with Mr. Vee.

Here again, I didn’t know what the effects would be because we didn’t have all this test data, I mean testing, behind us that we had on the other ammunition. While the design on the firing pin, to lighten it, which was subsequently done by Colt, was a relatively simple thing, and in my opinion, wouldn’t detract from the performance of the weapon any. As I say this weapon was tested for years and years and before this inadvertent firing ever come up and it come up because probably we had a batch of ammunition where the sensitivity level on these primers were on the low end, or, I should say, the high end of sensitivity, and also, the fact that there were firing the weapon in a way that they formerly didn’t before, which was single loading, when it was an automatic weapon.

Usually the weapon was loaded from the magazine and when the rounds were stripped out of the magazine like it was intended to be used, this slowed the bolt down enough that you didn’t have the impact velocity to cause an inadvertent firing.

There were actually two things that I took exception to on that. I didn’t sit in on the Board that came up with the ammunition specification. I wasn’t asked to. I am not in the ammunition business. But, I have a good deal of interest in the ammunition due to the fact- usually you can’t change the ammunition without causing a change in the performance of the weapon.

Stoner claims that the slamfires that occurred with his design, were due to the USMC not using the weapon properly, is in fact, pure hogwash and denial. It is unreasonable to design a rifle that can only be fed from the magazine. Stoner would have known the KD course of fire required loading the rifle single shot, both standing and prone slow fire. In this case, Stoner only knows about primer sensitivity as a conceptual basis. He does not know how much energy is required to ignite an average primer, and he does not know the kinetic energy of his firing pin. It turns out, if you study this, the kinetic energy of his early firing pin was always above the "none fire" limits of commercial primers. None fire is a very important safety criteria: no primer is supposed to ignite when hit by a firing pin whose kinetic energy is less than the "none fire" limit. Stoner's design, the primers were always being hit by a firing pin whose kinetic energy exceeded the "none fire" limit.

The Army could have put a spring under the firing pin, such as is done on the AR10 mechanism

View attachment 993185

but I am certain the Army did not want to add an extra part to their inventory, so they lightened the firing pin, and made a less sensitive primer. This is the top drawing for the #41 primer.

View attachment 993186

The less sensitive primer is something Stoner comments on, because he is worried about the energy output of his ignition system in extreme conditions. And this can be a real problem.

Now you will find mechanisms were the mainsprings have weakened over time, and they will misfire, particularly in cold weather. Been there! And, I see Bullseye pistol competitors who are using the weakest mainspring, and recoil spring, in their 1911's, to use the lightest recoiling loads. To day, no one has had problems with mainsprings, but they are always frustrated with their recoil springs causing failures to eject.

I recommend reading the section “Primer Sensitivity” in the book “Ammunition Making” by George Frost. When Mr Frost was in the business, revolvers were very common on the firing line. And to achieve the lightest double action pull, for timed fire and rapid fire, competitors used the lightest mainsprings they could find. Mr Frost comments that these shooters had to find the most sensitive primer lots for reliable ignition.

One thing that is a hardware issue is off center firing pin strikes.

Ideally, the firing pin should strike the primer right at the peak of the anvil.

View attachment 993187

The further offset the firing pin strike is from the anvil tip, the more energy it takes to have reliable ignition, and at some distance from center, the round won't fire.

View attachment 993188

I have a Ruger #1 rifle in 35 Whelen.
View attachment 993189

It misfired. The 35 Whelen has a small, slight shoulder, and that has caused misfires for me in other 35 Whelen's.

View attachment 993190

This is the only cartridge that I size the case for zero clearance in the chamber, the case shoulder is resting hard on the chamber shoulder, and there might be a slight crush up when I close the bolt. I was given advice to go for a 35 Brown Whelen, which has a sharper shoulder, but, I had not encountered misfires due to shoulder size, slope before. My Ruger misfired badly, even after switching to Federal LR primers, and installing a Wolff extra powder main spring. The thing was, the firing pin offset on the primer was bad, according to Ruger, 23 thousands from center. Ruger did fix the thing, by centering the breech and ignition is reliable.

But this is something that centerfire shooters should know about, and not accept sloppily made firearms from manufacturer's. If the firing pin is not striking the center of the primer, then, misfires can happen.

Ok Slamfire, thats a new one to me! Please elaborate on the "Dippity DO" smeared on the cartridges, and the reasoning behind it. Thanks Buddy

 

[Wireman]

Well, thanks for all the firearm design history especially the M16 firing pin trivia. Let me point out that every single successful firearm throughout history has gone through a series of trials and improvements both before leaving the design desk and after it has been in use. You just can't find every flaw or potential safety problem until it happens somewhere, sometime. Look at the Ruger MK IV. Someone somewhere thought it was a good idea to place the safety in the 50% engaged position and pull the trigger. Doing this would never even occur to most people. But practically overnight we hear of a "design flaw" in the safety.

The M16 firing pin plot is a good example of a red herring. Someone, somewhere has a slam fire and everyone jumps to the conclusion that the M16 needs to be re-designed, needs a firing pin spring and is "inherently flawed". The M16 does not need a modified or a titanium f.p. Given the correct ammo with correct primers there isn't going to be a problem. Running target .223 ammo in a military firearm is a totally different subject. As Forest Gump said, "Stupid is as stupid does, Sir". Many times you will see dramatic photos of pierced rifle primers which somehow "prove" that either the primers are defective (too soft) or the f.p. is too heavy, and etc. etc. They never give you the real data on barrel type, chamber type, headspace, cartridge loads and so on. And, for the record, it is not the f.p. that pierces a primer. The problem is caused by the out-of-spec (i.e. too large) f.p. hole in the bolt, which, along with overcharged rounds, acts like a paper punch. Many times, replacing the bolt will fix your issue. I'm just pointing out that photos of pierced primers or lightly dented primers tell us nothing, even though it makes for entertaining conversation.

 

[rfwobbly]

I test a lot of powders and various handgun loads out of general scientific interest, and because I have a home range that makes it convenient and possible. I have a well-cared for ProChrono on a professional camera tripod and typically get good numbers.

Winchester, CCI and Federal were used pretty much interchangeably... with the Federal preferred in guns with lightened hammer springs. But within the last 18 months I have begun to note somewhat wider SD spreads when I use Winchesters. These primers were all from the same lot. No problems with ignition or velocity... just the reported SD numbers. I'm very careful to use precise loads and a single brand of brass. I'm a retired test engineer so the whole process is tightly scripted.

Has anyone else seen this ?

 

[Slamfire]

Ok Slamfire, thats a new one to me! Please elaborate on the "Dippity DO" smeared on the cartridges, and the reasoning behind it. Thanks Buddy

I started shooting NRA across the course service rifle just after the Garand had left the scene, but before the AR15 replaced the M1a on the firing line. Basically, once the AMU started winning the Service Rifle Championship, with their NM M16’s, which was around 1995, the M1a disappeared quickly from the firing line. It is my recollection that 1996 was the last time the Marine Corp Rifle Team used the M14 as an across the course service rifle. In 1997 the Marines all had match M16’s. This is over 20 years ago and so the memory of the M1a as a match rifle is probably fading, and so were its peculiarities as to ammunition and case life.

At the time, experienced shooters recommended that cases would last only four or five reloads, which is about 5 to 6 firings, and to discard the cases before the case heads came off in the rifle. They would show me their cases, some I would take home, section them, see for myself how much severe case head stretch had developed. Garands and M1a’s are hard on brass:

I met a Distinguished HM who was shooting lubricated cases in his M1a. He left the RCBS case lube on his cases, never tumbled the lube off, and he said he could take a set of brass all shooting season. He was a gunsmith and a shooter who had won every XTC medal you could get, with lubricated cases, so his credibility was high. Like others I had read Hatcher’s Notebook and its warnings about greased bullets, and of course read all the gloom and doom predictions from in print gunwriters about oil/grease on cases, but here was something that was clearly working out differently from the prognostications of the authority figures.

Cost is an important consideration to me. There are those to whom case life and case cost are irrelevant, but few people got to retire with footlockers of free military brass. I have noticed that new “bargain” 308 Win is priced $25.00 for twenty rounds, so brass has become even more expensive over the years. While I cannot speak for others, but for me, saving money is important: the cost of replacing cases after five firings is significant, especially if you are shooting an M1a to earn the Distinguished Rifleman’s Badge . Being able to amortized the cost of a set of brass, 10 or even 20 firings, results in considerable cost savings over tossing the brass after five firings.

Brass life in a bolt rifle can be orders of magnitude higher than what a gas gunner can expect. Bolt rifles are easy on brass, less scratches and dents, and the brass is not stretched on extraction because the bolt is opened after chamber pressure is zero. The primary cause of case head separations in a bolt gun is due to excessive set back of the shoulder during resizing. Cases are really meant to stretch once, and not more than 0.006”, which is the average distance between “Go” and “No Go” on a headspace gage. If cases stretch more than that, depending on a number of variables, cases will break.

Garands and M1a’s, are much harder on brass than bolt rifles. Gas guns are very hard on brass because they unlock while there is still pressure within the barrel. Col Chin, in his Machine Gun series, https://www.ibiblio.org/hyperwar/USN/ref/MG/index.html calls this the residual blow back effect. Unlocking while there still is pressure in the barrel pressure is deliberate, engineered into the timing of the mechanism, and adds to reliable function of the mechanism. The residual blow back effect will pop the case out of the chamber as long as barrel pressures are low, less than 650 psia, and if case to chamber friction is low. However, since the case is moving, with the insides pressurized, this also has the effect of stretching the case. Hatcher explained, in Army Ordnance Magazine, March-April 1933, how cases stretch and why lubrication is essential in retarded blow back mechanisms:

Automatic Firearms, Mechanical Principles used in the various types, by J. S. Hatcher. Chief Smalls Arms Division Washington DC.

Retarded Blow-back Mechanism………………………..

There is one queer thing, however, that is common to almost all blow-back and retarded blow-back guns, and that is that there is a tendency to rupture the cartridges unless they are lubricated. This is because the moment the explosion occurs the thin front end of the cartridge case swells up from the internal pressure and tightly grips the walls of the chamber. Cartridge cases are made with a strong solid brass head a thick wall near the rear end, but the wall tapers in thickness until the front end is quiet thin so that it will expand under pressure of the explosion and seal the chamber against the escape of gas to the rear. When the gun is fired the thin front section expands as intended and tightly grips the walls of the chamber, while the thick rear portion does not expand enough to produce serious friction. The same pressure that operates to expand the walls of the case laterally, also pushes back with the force of fifty thousand pounds to the square inch on the head of the cartridge, and the whole cartridge being made of elastic brass stretches to the rear and , in effect, give the breech block a sharp blow with starts it backward. The front end of the cartridge being tightly held by the friction against the walls of the chamber, and the rear end being free to move back in this manner under the internal pressure, either one of two things will happen. In the first case, the breech block and the head of the cartridge may continue to move back, tearing the cartridge in two and leaving the front end tightly stuck in the chamber; or, if the breech block is sufficiently retarded so that it does not allow a very violent backward motion, the result may simply be that the breech block moves back a short distance and the jerk of the extractor on the cartridge case stops it, and the gun will not operate.

However this difficultly can be overcome entirely by lubricating the cartridges in some way. In the Schwarzlose machine gun there is a little pump installed in the mechanism which squirts a single drop of oil into the chamber each time the breech block goes back. In the Thompson Auto-rifle there are oil-soaked pads in the magazine which contains the cartridges. In the Pedersen semiautomatic rifle the lubrication is taken care of by coating the cartridges with a light film of wax.

Blish Principle….There is no doubt that this mechanism can be made to operate as described, provided the cartridge are lubricated, …. That this type of mechanism actually opens while there is still considerable pressure in the cartridge case is evident from the fact that the gun does not operate satisfactorily unless the cartridges are lubricated.

While neither the Garand or M1a are retarded blowback actions, cases are still stretched by the residual blow back effect engineered in these mechanisms. This pressure curve is of the Garand gas system. Do notice that unlock is complete when pressures are 600 psia. The case is being extracted for a distance of half inches before pressure is zero.

These cases were fired lubricated with Johnson Paste wax, as can be seen with the case gage, the shoulders have moved, as the case moved, during extraction. These cases were sized between the Go and No Go of this gage, and yet, because they were pulled out of the chamber during the residual blow back period, the case shoulders moved forward to fill the void. If these cases had not been lubricated, instead of the shoulder folding out to the contours of the chamber, the case sidewalls would have been stretched, damaging the case and leading to case head separations.




Case life is not a concern of the military, they don’t expect Soldiers to reload their ammunition, but for civilian shooters desiring to maximum the case life of a round fired in a gas gun, case life can be greatly extended by the practice of cartridge lubrication. Case lubrication will prevent the case neck and shoulders from adhering to the chamber, so that when the case is extracted under pressure, case sidewalls are not stretched. I am of the opinion that lubricated cases will improve extraction reliability because pressure is not zero, some part of the case is being dragged against the chamber. This is the primary reason M16’s have “extractor lift”. The case drags in the chamber and follows off the bolt face. Increasing case to chamber friction always reduces extraction reliability. Lessening case to chamber friction always improves extraction reliability.




The picture below showing case head stretch are typical dry cases fired in a M1a or a Garand. This was from a shooting bud and it was five times fired. Scratches are from a bent paperclip inserted in the case mouth, I was trying to find the side with the deepest stretch ring.

When I resized my cases, I sized the cases to gage minimum or if the brass is to be fired in only one M1a, I sometimes push the shoulder back 0.003” from the chamber headspace. It turns out, it is easier just to size to gage minimum. Primarily I use RCBS water soluble case lube, because the stuff sizes well and is easy to wash off in soap and water. I size my gas gun cases in small base dies. I set up the dies with cartridge headspace gages.





Most of rounds I fired I coated with Johnson Paste wax. I believe the hard, durable wax in Johnson Paste wax is ceresin wax, the same wax that John Pedersen used in his wax coating of the 276 Pedersen rifle:

Patented Nov. 4, 1930

PATENT OFFICE JOHN DOUGLAS PEDERSEN, OF SPRINGFIELD, MASSACHUSETTS

http://www.google.com/patents/US1780566

In the preparation of cartridges having metal cases for storage and for use, it has been found desirable to apply to said metal case a relatively thin coating of some protective substance which will preserve said metal case for comparatively long periods of time against-deterioration, such as season cracking. In the present invention, the material for said coating has been so chosen as to perform the additional function of acting as a lubricant for the case of the cartridge, both for facilitating introduction into the chamber of the gun and the extraction thereof after firing. The most suitable wax which I have found for this purpose and which I at present prefer is ceresin, a refined product of ozokerite; but I wish it to be understood that other waxes having similar qualities may exist which might serve equally well. Some of the desirable features of ceresin are that it is hard and non-tacky at ordinary temperatures having a melting point somewhere between 140 and 176 Fahrenheit. It is smooth and glassy when hard and does not gather dirt or dust. However, when the ceresin on the cartridges is melted in the chamber of a gun, it becomes a lubricant.

Other lubricating waxes have been employed for coating cartridges, and the method most generally pursued for applying said coating to the cartridge case has been to prepare a heated bath of a solution of the wax in a suitable solvent, dip the cartridges therein so that a film of the solution will adhere thereto, and finally withdraw the cartridges to permit the solvent to evaporate from the coating film. This former process is comparatively slow and has been found lacking in several important respects.



Even though it was a time consuming process, for match ammunition, I preferred coating my match cartridges with Johnson paste wax. And it was for precisely the same reasons as John Pedersen gave: It is smooth and glassy when hard and does not gather dirt or dust If you have ever shot in an XTC rifle match, you are on the field all day. None of the ranges I shot had running water, for bathrooms: you went around the berm. Because I could not wash, I preferred to not have industrial or automotive greases all over my hands. Another thing in XTC matches, you don’t get a lunch break. You munch on whatever you brought in the few minutes of between relays and preparation periods. I did not want to be eating axle grease with my sandwich. So, for match ammunition, I preferred Johnson paste wax.

At Camp Perry in cold weather I had bolt over rides with some of my Johnson paste waxed rounds during a rapid fire stage. This stopped when I polished the rounds with a rag. Previous to that I shot the rounds with swirls and gobs of paste wax but evidentially that caused sluggish round rise in the magazine in cold weather. From then on I polished my rapid fire rounds and have never had a bolt close on an empty chamber even in rapid fires sequences in snow. For slow fire rounds, I left the gobs of wax alone.

I don’t like the feel of greasy cases and if I had time between matches I washed the cases to remove the RCBS lube, primed them clean, loaded them with powder and bullet, and after that, applied paste wax. If I did not have time I fired the cases just as they came out of the die, minus whatever RCBS lube which was lost in handling. I never had a primer dud, even though I primed hundreds of cases that had a RCBS lube coating. I ran a number of experiments with various lubes. Leaving thick coatings of heavy greases is objectionable as grease particles are blown into the air, some out of the action, some out of the barrel. I had 1000 rounds of 7.62 CAVIM and I fired most of them in a FAL. FAL’s are very hard on brass and I had this stick wax, so I experimented with the stick wax. Stick wax is tenuous grease used to lubricate saw teeth. It really sticks to stuff. I dropped lumps of stick wax in a plastic bag with handfuls of CAVIM and shook vigorously. Both case and bullets were unevenly coated with globs of stick wax. When I fired this stuff it was as if a grease bomb went off. The mechanism became coated in stick wax, and I was coated in stick wax. My shooting glasses had to be frequently cleaned, my hands were greasy, my clothes were greasy, overall, it was messy. Because it was so messy, I later spent hours wiping the cases to reduce the amount of stick wax covering the cases. This was better, but I still had stick wax over my hands, clothes, and the stuff does not wash off easily. Stick wax does exactly what it is supposed to do: stick to the surface.

Some of the lubes I tried include Imperial sizing wax, Mink Oil shoe polish, Hornady Unique case lube, Lee lube, wire pulling wax, lubriplate greases and many combinations of axle grease and wheel bearing greases. I oiled cases with automotive oil. I will never again use stick wax. I never ever had issues with case damage or unusual case damage such as “serrations” as one Hatcherite claimed would happen with Imperial sizing wax. Any one claiming such nonsense has to be confabulating experiences from their own fantasy land of physics.

After much testing , I came to the decision that I preferred dry coatings. Even so, with RCBS water soluble, after all the handling that occurs with trimming, priming, dumping the powder , seating the bullet, the amount of RCBS case lube left on the case does not leave objectionable residue in the mechanism or eyeglasses.

The picture below are of sectioned cases, R stands for reloaded, R5 five times reloaded, etc, all of these cases the shoulder was set back about 0.003” and the cases fired in my M1a. I do not visually see any evidence of case wall thinning from those cases reloaded 5 times (6 times fired) , R18, or R22. As long as the case is not excessively stretched during firing or extraction, there is no reason for the sidewalls to thin.

My basic conclusion is that if cartridge brass does not failure through case neck cracks, body splits, and you have not stretched them so they develop case head separations, you can load them until the primer pockets get too large. I quit shooting these cases because it became easy to insert the primers in the pocket. Loose primer pockets will release primers when the round is fed into the chamber. I have had jams due to loose primers in a number of semi automatic mechanisms. I had lots of jams in my 45 ACP M1911’s due to range pickup AMERC brass.

I found that I needed to periodically ream the primer pockets: the pockets became shallow. Don’t know why unless the primer pocket collapses over time. As incidental contact with the primer can cause a slamfire or an out of battery slamfire, keeping the primer below the case head is a safety critical issue.

I believe that lubricated cases will produce more consistent accuracy than dry cases. Chambers foul and they foul unevenly. I am of the opinion that irregular binding occurs when cases adhere to the chamber. Lubricated cases evenly transfer the thrust to the locking mechanism. For their roller bolt rifles, which use gas lubrication to break case friction, HK used to make a statement to that effect on their web page.



I don’t think it is any coincidence that all match 22lr ammunition is liberally greased from rim to bullet tip. I am also of the opinion that all semi automatic mechanisms eject more reliably if the case to chamber friction is reduced. While the M1a has been developed to an accurate service rifle, I believe any inaccuracy due to case friction is in the noise level for this mechanism.

I can say I earned my Distinguished Rifleman’s Badge and won a Regional Gold with lubricated cases in the M1A. My accuracy and function with lubricated cases was more than acceptable. My case life was orders of magnitude greater than those who fired dry cases, so I saved money. That has to mean something. I shot two barrels out on one M1a, all with lubricated cases. I did not notice any unusual wear patterns on the bolt, operating rod, receiver.

Lubed cases do not work well at all for black powder cartridges and I recommend keeping the case and chamber dry with blackpowder cartridge firearms. BPCR shooters breathe through a tube in the chamber to moisten fouling and several have informed me that if they did not swab the chamber to dry, their cases had been pulled up the throat!. I have been told the case goes up the barrel far enough to see rifling marks, about a tenth of an inch. Obviously black powder combustion pressures are not enough to fix the case in place. Smokeless gunpowders have a high enough and quick enough pressure curve to fix the case in place.

 

[Slamfire]

Due to space limitations, I have split the post into two parts

I think it is very interesting that Varmit Al’s finite element analysis shows that in an unreal state of zero friction, the cartridge case collapses in a heap:

Varmit Al analysis of pressure http://www.varmintal.com/a243z.htm

This is fun to watch



The chamber in my JM Marlin must have been reamed with a sausage instead of a reamer. It is huge, I think I could rent it out as an Zeppelin hanger. Cases fired in the thing, the shoulders blow out an amazing distance. I hope this picture is self explanatory:



The case shoulder moves about 0.025" on firing. Now if I fired dry cases in a dry chamber, the front of the case would adhere to the chamber, fixing the cartridge in place. Then, as pressure built up, the sidewalls would stretch to allow the case head to the bolt face. The end result would be case head separations and a very short case life. To avoid this I am fireforming my cases by lubricating them.



By lubricating my cases I prevent sidewall stretch on the first firing. What is in the picture is a stiff hairgel, which I experimented on as a bullet lube. These hair gels are 99% vasoline and the rest is perfumes. Vasoline will work equally well, in fact, case lube will work equally well. Just a little dab will do you, rub the vasoline smooth, chamber the round, and fire the things, like this:







On first firing, instead of the case adhering to the chamber sidewalls, the case slides to the bolt face, the shoulders fold out, and what you end up having is a stress free perfectly fireformed case.

Lee Enfields are well known for eating cases, and yet Parashooter took his cases an extraordinary number of reloads.



Due to the cost of belted Magnum cases, 30-30 cases, and cases necked up or down, firest fireforming, I lubricate them so the case comes out of the chamber a perfect fit and stress free. After the first firing, I size the case so the shoulder is not bumped back by more than 0.003". Actions that are very flexible, such as the Lee Enfield and lever actions, lubing the case neck just before firing will provide enough lubrication to prevent sidewall stretch. I have used a lot ot Johnson paste wax. Johnson Paste wax works great, it dries hard, and is similar to what Pedersen used on his cartridges:





There were a huge number of pre WW2 weapons that used oilers and greased ammunition. Almost all of these weapons were retarded blowback mechanisms, and LTC Chin documents a number of them in Vol I of the Machine Gun Book. https://www.ibiblio.org/hyperwar/USN/ref/MG/index.html

It is interesting to read articles and books before WW2 and find out how many Ordnance Bureau Employees knew of case lubrication and the reasons for it.

Automatic Arms, their History, Development and Use
published 1941

Melvin M Johnson

Certain weapons of the blowback and retarded blowback types require lubricated cases. It is perfectly obvious that lubrication of the ammunition facilitates functioning in automatic weapons, provided the breech lock is designed to keep the breech substantially closed until the pressure has dropped to a safe limit. Where the breechblock moves back during the interval of critical pressure in any measurable degree, it is essential that the rear end of the cartridge case wall should be extremely rugged so as to withstand the pressure developed in the case without the support of the chamber wall.

The conventional .22 autoloading rifles and automatic pistols generally require a certain amount of lubrication on the cases. In these weapons the breechblock can actually move back some what before the bullet is out of the muzzle. However, the case is sufficiently strong to stand a small amount of movement prior to the time when the pressure has dropped to a safe limit. Incidentally, a very large percentage of the malfunctions experienced with .22 caliber automatics could be avoided by the use of a little extra lubrication in the form of oil or grease on the cartridges or applied to the magazine body. The application of a light oil to the magazine tube or its equivalent is especially helpful in cold weather, when the grease on the greased cartridges is usually to hard to be effective.


Of the anti aircraft weapons on the WW2 battlefield, the Oerlikon was the most common mechanism. And it required pre greased ammunition. The weapon was bolted down, or attached, and amazing number of planes, ships, trucks, shore installations, etc. Germans and the Japanese used the things on their aircraft, and so did the USAF and the British Air Force.





No one I know has a 20mm machine cannon, and I have never read an article in the popular press about the things, so this weapon, and its need for lubricated cases, has been totally forgotten by the civilian shooting community. The Oerlikon was still in inventory during Vietnam, but by then, an oiler had been added, as pre greasing ammunition was time consuming. I found a Navy test report from the 1950’s, and right after WW2, a lot of experiments were conducted in an attempt to find a way to stop having to grease the ammunition. The Navy tried fluted chambers, waxed ammunition, Teflon coated ammunition, combinations of Teflon with oil or wax. In the end, they put an oiler on the weapon.

This report used to be available to the public on a Navy site, and then they took it all down. I have copied and pasted only the introduction.

NRL Memorandum Report 562

A LABORATORY INVESTIGATION OF CARTRIDGE LUBRICANTS FOR 20MM F.A.T.-16 STEEL CARTRIDGES
Author V. G. FitzSimmons

January 1956

Introduction

In May 1955 a conference was called by the Bureau of Ordnance for the purpose of determining procedures and test methods for evaluating a new type of 20MM steel cartridge F.A.T.-16 manufactured for the Army by the Proctor Electric Company of Philadelphia, Pa. This cartridge had been designated to replace the M21A1 brass cartridge, which is in use by the Navy. Army Ordnance has cognizance of the production of this type of cartridge and of the finishes used for protection and lubrication. The primary concern of the conferees was about the effects on gun performance of the wax coating used on the new steel cartridges. In attendance were representatives of Codes Relb, Re2a and Re8a of the Bureau of Ordnance and Code 6170 of the Naval Research Laboratory. In the past decade tests at the Naval Proving Ground had always demonstrated that waxed ammunition was unsatisfactory. Also, it was known that the Army and Air Force had frequently encountered storage and service problems caused by the use of wax on 20MM brass ammunition. Therefore, naval procurement of Army manufactured M21A1 brass ammunition had excluded wax coatings for 20MM cartridge lubrication. Since early in the Korean War it has been naval practice to oil cartridges just prior to use '(reference -(a)). Research at this Laboratory on dry film lubricants for cartridges, began in September 1950. In references (b) and (c), were listed the guides which were to be used in determining the value of a dry lubricant coating for ammunition. The most important conclusion of that investigation was that a thin film of polytetrafluoroethylene (Teflon) was the most satisfactory dry lubricant coating for cartridges. This conclusion was confirmed in the NRL reports of references (d), (e), (f), (g), (h), (i), and (J). During this research and development program Code ORDTS, O.C.O., was kept fully informed by liaison with Code 6170 of NRL. As a result, representatives of Frankford Arsenal asked for and received technical guidance from NRL in establishing Teflon coating facilities at the Frankford Arsenal and later at the Philadelphia plant of their contractor, the Proctor Electric Co. Through various visits the NRL representative became familiar with the manufacturing processes involved and with the various coatings being applied to the Army 20MM F.A.T.-16 cartridges. For a number of years the Army has been developing steel cartridges of all calibers and also protective coatings for them. A varnish-like, epoxy-phenolic resin coating, identified by the producer (the Stoner-MNudgeCompany) as "Case-Cote" was developed which provided excellent corrosion protection to steel; however, since this varnish coating produced gun malfunctions such as cartridge sticking, additional lubrication was required. In the past either ceresin wax or microcrystalline wax had been used by the Army as cartridge lubricants. Ammunition storage difficulties with ceresin wax films led the Frankford Arsenal to use a higher melting point microcrystalline wax as an outer coat over the "Case-Cote" varnish. After the Frankford Arsenal learned of the NRL work with Teflon coatings for cartridges, an Army Ordnance project was established at the Proctor Electric Company to put Teflon coatings on the steel F.A.T.-16 cartridges manufactured there. However, certain difficulties arose in obtaining good corrosion resistance with Teflon, apparently due to the manufacturing methods used. The steel F.A.T.-16 cartridges were manufactured by a completely cold forming process (there was no annealing between drawing operations). As a consequence, the cartridge metal was cold worked in the presence of highly alkaline die lubricants. Apparently, this process so affected the metal surface of the cartridge that Teflon films applied thereon were porous and would not provide sufficient corrosion resistance even though the Teflon was adequate as a lubricating film. Therefore, the Proctor Electric Company developed as an alternative, a mass production process for applying Teflon on top of the "Case-Cote" varnish. This method imparted good corrosion resistance to the cartridges. Over 100,000 steel F.A.T.-16 cartridges were Teflon coated in this way and were sent to Aberdeen Proving Ground to be compared in firing tests with ammunition coated with "Case-Cote" and a wax outer coat. Apparently some confusion arose as a result of the performance observed at Aberdeen of these two types of coated steel cartridges. The manufacture of Teflon-coated ammunition was subsequently stopped at the Proctor Electric Company plant. This may have been caused by the conflicting results of the Aberdeen tests. However, interest in Teflon coatings for cartridges has continued at Frankford Arsenal, and Teflon coatings have since been applied there to a variety of steel cartridges of various calibers. Purpose of this Report In the aforementioned conference, Code 6170 of NRL agreed to investigate some of the properties of the F.A.T.-16 steel cartridges coated with the waxed "Case-Cote" film.. 'Since there was a question about the suitability of such waxed coatings for naval use, the NRL tests also were to be made on the steel cartridges from the same production lot but coated with Teflon. 2The proposed NRL test program was outlined as follows at the planning conference: (1) Several hundred Proctor Electric F.A.T.-16 steel cartridges were to be coated at NRL with Teflon. It was also proposed to determine why good corrosion resistance had not been obtained by the Proctor Electric Company. (2) Single round firing tests were to be made with a dry lubricated (Teflon coated) M-3, 20MM gun to compare the lubrication given the cartridge by wax on "Case-Cote" with that given by a Teflon coating. A Teflon coated M-3 gun was to be used to prevent the accidental presence of oil either on the ammunition or in the gun chamber. (3) Inspection and evaluation of the fired cartridges was to be made to provide data concerning possible differences in metallurgical performance between uncoated steel and brass cartridges. This reports the results of the NRL investigation of the lubrication of 20MM, F.A.T.-16 steel cartridges. Corroborating information obtained by an NRL representative at a conference at Frankford Arsenal. 7 July 1955, is also presented here.

 

[giggitygiggity]

CCIs are my preferred primers. I’ve had the fewest issues with them and by issues I mean light primer strikes (maybe one in every 1500-2000). I used Tula primers and they were, by far, the worst. I had about 2% light primer strikes in a variety of firearms; and yes, I ensured that the primers were fully seated so as to not have one firing pin strike fully seat the primer and a second to actually ignite it.

 

[reloaded_in_pa]

I've had no issues with CCI's or Federals. I still have plenty of S&B but rarely use them because they seat with a lot of effort.