M1 Carbine primers

[greyling22]

I use a cci small rifle primer. I also use a tula small rifle primer.

 

[Slamfire]

have been shooting this carbine for about 35 years
I have never seen any "yet"

BTW: this is my home defense weapon--it gets test fired quite a bit

Clock time is not the best way to consider risk or frequency of slamfires. Given that the risk of a slamfire is around 1:35,000 per shot, the number of shots fired is a better measure of risk. As an example, I figure I shot my first military carbine with military ammunition over 20 years ago, sometime in the middle 90’s and I acquired several CMP carbines around 2003. I have only shot military ammunition in my carbines. Shot them a couple of times in local carbine matches before I gave up on the things. Accuracy with the things is so poor that they are frustrating to shoot. I have shot maybe 300 rounds, never a slamfire, and clock time keeps on clicking. In a couple of centuries I can claim hundreds of years experience and never a slamfire in a carbine. Hey, maybe I will get lucky and will still be here in 2213.

Now, as an idea of how many rounds you have fired through yours, how many barrels have you shot out? A reasonable number is 5000 rounds for a typical barrel, maybe more in a Carbine, before it is worn out. Rimfire barrels last much longer, at Bristol IN, during the Small Bore Championships, a gentleman I was talking to estimated he had 60,000 rounds through his Anschutz, another I met a couple of years ago estimated he had 700,000! Centerfire barrels firing jacketed bullets don’t last as long as rimfire barrels obviously. So, how many barrels have you worn out on your carbine?

A bud of mine, who has a President’s 100 patch, and this year was in the President’s 100 shoot off, last I talked with him, he had 2 in battery slamfires in his AR15’s with federal match primers. I learned that a couple of years ago from him, and he stopped using federal primers after the second one. A slamfire counts for a big fat zero on your score card in highpower competition. You fired the shot, it hit nothing, and your score for the day is ruined because you just dropped ten points. I know he has shot barrels out on his competition AR’s, so I figure he has fired at least 60,000 rounds in competition over the decades I have known him. Had two slamfires in AR’s and does not want any more.

Slamfires are rare, they happen, by using the most sensitive primer you can find, you just increase the chance the odds of one happening, on a per shot basis.

This is a lottery you don't want to win.

On a side note, regarding the post by Slamfire. When it comes to priming issues or slamfire issues (as in actual slamfires) I enjoy his post. Slamfire takes the time to add supporting material to his post. He defines why he post what he post and that counts

Thanks. As we all have seen, denialists don’t have any real analysis or supporting documentation. By themselves, hate, ignorance, superstition, are self supporting. However, once you cross into the factural world, I believe if you want to make a good case, you have to make a good case.

 

[Slamfire]

Something about Murray’s video, what he is doing is absolutely insane, in my opinion. https://www.youtube.com/watch?v=xj3QtnUWCwQ It is only by good design features, and a lot of luck, that his SKS does not go off out of battery. The Garand mechanism is an early mechanism, does not have a positive means of holding the firing back, but incidentally, neither does the FAL or the SKS. But their SKS and FAL designers created a feature that keeps the breech face, and the firing pin, out of alignment, until the bolt is in battery. The Garand mechanism does not, its firing pin is totally in line with the primer, unrestrained, and that is why Garand mechanisms not only slamfire in battery, due to primer sensitivity, but will actually slamfire out of battery!. The firing pin can hit the primer in a Garand mechanism and the lugs don’t have to be engaged. If Murray had jacked the firing pin forward on a Garand/M1a/M1 carbine or Mini 14, the end result would have been an out of battery slamfire. Garands and M1a’s have the most out of battery slamfire reports of any mechanism. In fact, about the only, though there are same reports for AR’s that make me wonder how the AR went off out of battery as the firing pin does not extend until the lugs are in battery.

To reduce slamfire frequency by reducing firing pin inertia impact energy , the Italians installed a spring in some of their Garands and BM 59 rifles.



Roland Beaver makes the same modification, for a charge, on Garands/M1a’s.


I have not found any slamfire incidents with roller bolts. The Germans designed an exceptionally safe design as the firing pin is positively held back until the bolt is in battery. Because the firing pin spring is so strong (I think it could be used as a valve spring) there is zero firing pin float once the lugs are in battery. This is a great design, in my opinion.

 

[CoalTrain49]

I understand wanting to have a margin of safety but my experience with several carbines is that harder primers like CCI 450 will cause FTF's. It's not that big of a problem but when you have two carbines and you can't get a 450 to fire in either one that tells me the primer is too hard. Someone else may have a different experience. I can't find any reloading manual that lists a magnum primer unless the powder being used is H-110. I have a supply of both and use both but I have better luck with 400's. I have also rebuilt my bolts and all my springs have been replaced. CCI primers are very hard anyway and the 450's are thicker than 400's. Here's the breakdown.

Small Rifle Standard

CCI 400 -thin .020" cup, not recommended for AR15 use by CCI/Speer. Good for .22 Hornet, .30 Carbine. See Note 1 at the bottom of the page
CCI BR4 - match primer with a thicker .025" cup.
Federal 205 - Mil-Spec cup thickness according to Federal - okay for 5.56mm. .0225" cup thickness.
Federal 205M - same as the 205 but the match version.
Magtech PR-SR - .025" cup thickness (not much feedback yet on this new primer as to AR15 suitability but with the same cup thickness as the Rem 7 1/2 it looks good so far)
Remington 6 ½ - thin .020" cup, intended for older, lower pressure rounds Remington says do not use for the .223 Rem or other similar pressure rounds. Good for .22 Hornet, .30 Carbine.
Remington 7 ½ BR - A match or "bench rest" primer. Lyman & Nosler classify this primer as a Standard. Remington says the compound is the same as the 6 1/2 but with a thicker .025" cup.
RWS 4033
Winchester WSR - some piercing issues noted when changed from silver to brass cup. Cup thickness is a bit thinner at .021". Most say they are good to go for the AR15 despite that, probably because of the hardness of the cup. Some feel they are less resistant to higher pressures.
Wolf/Tula Small Rifle SR #KVB-223 - soft, sensitive copper cup, not recommended for AR15/military rifle use or high pressure rounds.

Small Rifle Magnum

CCI 450 - same thicker .025" cup as the BR4 and #41.
CCI #41 - commercial version of the fully-qualified DOD primer for use in U.S. military ammo. With this primer there is more 'distance' between the tip of the anvil and the bottom of the cup than with other CCI SR primers. .025" thick cup. Same primer mix as CCI 450.
Remington 7 ½ BR - A match or "bench rest" primer. Hornady, Handloads.com, and Chuck Hawks classify this primer as a Magnum, differing from other sources that classify it as a Standard. .025" cup thickness.
Wolf/Tula Small Rifle Magnum SRM - hard, less sensitive brass cup intended for AR15/military rifle and high pressure rounds - #KVВ-5,56M.
Wolf/Tula Small Rifle 223 SR223 - #KVB-223M "This is the newest primer available in the Wolf line. It is ever so slightly hotter than the small rifle magnum primer and it comes with a brass colored thick cup. This primer can be used in place of the SRM primer or used when a different powder is used that is hard to ignite."

 

[ArchAngelCD]

CoalTrain49,
I'm sorry but if you are getting round that fail to fire when using a CCI-450 primer it's not the primer, it's the gun or both guns in your case. Companies manufacturing primers spend millions on research and testing to insure their products are safe and will perform reliability in all guns which are in proper operation condition.

The difference in cup thickness is only five one-thousands of an inch (.005") which will not cause malfunctions unless something is wrong with the gun or there is user error.

Magnum primers will burn a little longer and a little hotter but not cause a nuclear explosion. In turn they are not made of armor plating either and are not so hard they will cause malfunctions.

I'm not doubting your reports but I'm sure you are the exception, not the rule.

 

[Slamfire]

Coaltrain49

If you are having misfires after replacing the mainspring, I am of the opinion you have a mechanical problem of some sort. This mechanism after all, was used in the Aleutians and in the winter of Korea, and went bang in the cold with mil spec primers.

According to TM 9-1276 the firing pin protrusion on a M1 carbine is 0.048” min to 0.065” max. This is worth checking.

Regardless of firing pin protrusion I would recommend disassembling the bolt and cleaning out the firing pin channel with a solvent and a pipe cleaner. This device makes bolt disassembly a snap:



Then I would check to make sure there is clearance between the firing pin tang and the receiver retraction cam. As you can see in this picture, my GI receiver provides plenty of clearance with the firing pin fully forward.



Lastly I would make sure make sure that you are fully seating the primer. Ream your pockets by hand, seat your primers by hand. While slamfire denialists were taught that only "high primers and your worn out gun cause slamfires", it turns out the high primer warning was a canard. High primers are the most common cause of misfires! For proper ignition the anvil must be firmly seated and the primer cake pushed into the anvil, this is according to the CCI article here:

Mysteries And Misconceptions Of The All-Important Primer
http://www.shootingtimes.com/2011/01/04/ammunition_st_mamotaip_200909/
Page 5 of 9

The real story is that Boxer primers leave the factory with the anvil higher than it would be when seated in a cartridge case. Seating so anvil legs touch the bottom of the pocket lets the anvil tip penetrate into the pellet of mix. The nearly universal recommendation of having the primer cup bottom 0.003 to 0.005 inch below flush with the case head exists to set the proper amount of priming mix between the cup and the anvil tip.

This critical distance is known as the bridge thickness. Establishing the optimum thickness through proper seating means the primer meets sensitivity specifications but does not create chemical instability. However, failing to set the bridge thickness through proper seating depth is the number one cause of primer failures to fire. The bridge thickness is too great with a high primer, even one whose anvil legs touch the bottom of the pocket

Of course, if a reloader is in the habit of putting washers underneath their primers, then the primer will be high, anvil firmly set, and of course a good whack on the primer will set the thing off.

 

[Walkalong]

High primers are the most common cause of misfires! For proper ignition the anvil must be firmly seated and the primer cake pushed into the anvil

It most certainly is. Comes up all the time.

 

[mdm]

A slam fire will not bother me as I always keep my rifle pointed in a safe direction...

This is good for the range, but

Bedroom: M1 carbine

You are talking about HD here. In you home where is the "safe direction"? The situation in a HD scenario would be too fluid for me to depend on a "safe direction". Through what door or window is the threat entering? Are they already in the house? If so, what room are they in? What friendlies are in the house? Where are they? In your home when you've determined your "safe direction", are you really not concerned about an AD due to a slam fire? I would be. If I have to grab my weapon and let the bolt fly the last thing I want to be concerned about is an AD whatever the cause.

I do a lot of shooting with my .30 carbine and it is one of my go to guns for the house. I use the CCI 400 primers and have had no issues with my rounds functioning as intended once I had it developed properly. I don't feel the #41 is needed and can in fact cause FTF which is totally unacceptable for a HD weapon.

This was a discussion on .30 carbine primers and degenerated into a discussion on AR primers. Just to contribute to the degenerated conversation, I use nothing but #41 primers for my ARs.

 

[Carl N. Brown]

No knowing the condition of all guns, all firing pins and all ammunitions, I would assume the possibility of a slam-fire and handle the gun accordingly (muzzle awareness at all times).

I have reloaded only a few hundreds of .30 Carbine, but have always bought small rifle primers. I have not noticed firing pin indents on ejected unfired rounds. That would not prevent debris or dirt from jamming the firing pin when I least expect it, or leaving the broken tip of a firing pin jammed in the bolt face, so again, muzzle awareness at all times.

And at the risk of starting another controversy, I belief that S&B uses small rifle primers in their pistol ammunition, due to my experience with a DA-only pistol that would fire Winchester consistently, and S&B on the first strike usually, but often required a second or third strike. One reason NOT to use small rifle primer in a pistol since the cups appear to be thicker material.

 

[HOWARD J]

@mdm
When the guy breaks into my house & I let the slide fly---YOU CAN BET YOU WILL BE THE FIRST GUY I TELL WHAT HAPPENED---DOES THAT MAKE YOUR DAY OR WHAT?

 

[Slamfire]

And at the risk of starting another controversy, I belief that S&B uses small rifle primers in their pistol ammunition, due to my experience with a DA-only pistol that would fire Winchester consistently, and S&B on the first strike usually, but often required a second or third strike. One reason NOT to use small rifle primer in a pistol since the cups appear to be thicker material.

I don’t believe in the slightest that S&B uses small rifle primers in their pistol ammunition, it is more likely that they make primers that are compatible with all those communist era pistols which have robust ignition systems and don’t have firing pin blocks. Take a look at a Tokarev pistol. No safety, no firing pin block, massive free floating firing pin. I will bet your pistol has a firing pin block, and one reason it is there is because of a race to the bottom, in terms of primer sensitivity, that has occurred because of inadequately designed ignition systems. Weak ignition system, shooters complain at the ammunition company for misfires, ammunition company responds by making primers so sensitive they ignite if rubbed against a Boy Scout. Again, read the words of wisdom on this by Mark Humpreville:: IT DON’T GO BANG:FIRES, HANGFIRES, MISFIRES AND SHORT ORDER COOKS IN JERSEY http://riflemansjournal.blogspot.com/2009/08/primers-it-dont-go-bang.html

 

[USSR]

Getting WAY afield from "M1 Carbine primers". Why, I'm so fearful of primers now that I'm thinking of buying flints.

Don

 

[CoalTrain49]

After reading all of this I've come to the conclusion that about the only reason my 450 primers won't detonate is due to the improper seating of the primer. I'm going to back up here and yield to experience and knowledge. The 41 mil spec primer and the 450 mag primer should work the same as all the others. If they don't it's probably the rifle or the seating of the primer.

But I'm still in the camp that any small rifle primer will work in a 30 carbine just fine if the headspace is good and the bolt has been maintained. These NATO mil spec primers didn't even come on the scene until the 90's which is after the M1 carbine was taken out of service. I believe they were developed for the higher pressure 5.56, at least that's what CCI would have you believe. I haven't seen anything in their info sheets that specifically says anything about the 30 Carbine. If they have I missed it.

http://lem.nioa.com.au/products/download/64/brochure-cci-primer-no-41.pdf

The M1 carbine was used in 3 wars without mil spec primers. The actions are robust and if properly maintained slam fires and FTF's should not happen. There is no reason to think that it was because of the type of primer used.

Great thread and thanks for the participation.

 

[USSR]

...I'm still in the camp that any small rifle primer will work in a 30 carbine just fine if the headspace is good and the bolt has been maintained.

And they will.

Don

 

[345 DeSoto]

THE most important thing about cleaning my brass isn't if they sparkle better than factory, or if you can shave in your reflection on the inside of the case. It's primer pocket cleanliness. If the pockets have crap in them, especially around the edges where the cup rests when seated, then that leads to problems down the road. SANITARY primer pockets is the reason I SS wet tumble...the sparkley part inside and out, is an added benefit. BTW, CCI 400's have worked flawlessly for me in my Penfield M1...

 

[Slamfire]

But I'm still in the camp that any small rifle primer will work in a 30 carbine just fine if the headspace is good and the bolt has been maintained.

Sure, they will all go bang, sometimes even when you don’t expect them to go bang. The second part is rare, but it happens.

These NATO mil spec primers didn't even come on the scene until the 90's which is after the M1 carbine was taken out of service. I believe they were developed for the higher pressure 5.56, at least that's what CCI would have you believe. I haven't seen anything in their info sheets that specifically says anything about the 30 Carbine. If they have I missed it.

The Army required “mil spec primers” as long as they have been making ammunition and contracting out for ammunition. Way back, when the Army actually made arms and ammunition in house, they understood the operating characteristics of their weapons and specified primers, powders, pressures, etc, that were appropriate for their weapons. Now the Army contracts out everything, they are experts on contracts and funding. There is no organic technical expertise, unless someone is just interested in the topic as a hobby. Back in the 60’s one of the last of the real technical experts came up with the primer requirements for the AR15. That is what the #41 primer is, a AR15 primer, it is not a 30 Carbine primer. Carbine primers are even less sensitive than AR15 primers. No one offers to the public a 30 Carbine primer.

During the Clinton primer scare, CCI decided to make their military primer product line available to the public. Winchester and Federal all make “mil spec” primers if they want to make or sell ammunition to the Government. Federal has seen its share of the AR15 market drop, probably due to slamfires, and they have recently offered their mil spec small rifle primer to the public. Assuming the non existence of mil spec primers because you never saw them is a false assumption. They existed long before you even heard of the concept.

The M1 carbine was used in 3 wars without mil spec primers.

Really? So our Soldiers all went to the hardware store and bought commercial ammunition? I have an ammo box of 30 Carbine made by Lake City, I guess they did not use any of that in any of the wars you are thinking about.

The actions are robust and if properly maintained slam fires and FTF's should not happen. There is no reason to think that it was because of the type of primer used.

What an amazing conclusion, backed up by nothing.

 

[USSR]

SlamFire1,

There is wearing VERY, VERY thin. You are simply OBSESSED with this whole slamfire thing. In regards to the .30 Carbine cartridge, the commercial ammo factories that produced it for the U.S. government were given a lot of latitude in producing ammo for them. Why, they were not even required to crimp the primers in place, even after the development and use of the M2 Carbine. In my experience, only WRA and WCC headstamped brass had crimps. I have zero doubt that when the government established the specs for the primers to be used in .30 Carbine ammo, they established the specs so that all currently used commercial primers met the specs.

No one offers to the public a 30 Carbine primer.

Au Contraire! It's called a standard small rifle primer. Sheesh!

Don

 

[CoalTrain49]

For those that want the numbers the LC ammo none fire/all fire tolerance was 6-36 in/ozs. and the primer cup thickness was .019", about the same as a regular SRP (CCI 400, WSR, Rem 6 1/2). CCI#41 (developed for the 5.56) none fire/all fire spec is 12-60 in/ozs. and cup thickness for both 41 and 450 is .025". Two different rifles and two different cartridges.

Now you can decide which one you want to use and which one can be used. I might add that Lake City ammo was used in a lot of carbines and it didn't have anything like a CCI 450 or 41 mil spec primer.

In this pdf is a winchester load to duplicate original standards. Notice that the primer is a WSR. Also note that the document comes from the CMP. Just for those who need supporting documentation.

http://www.odcmp.com/Training/CR/CarbineNotes.pdf

 

[Slamfire]

For those that want the numbers the LC ammo none fire/all fire tolerance was 6-36 in/ozs. and the primer cup thickness was .019", about the same as a regular SRP (CCI 400, WSR, Rem 6 1/2). CCI#41 (developed for the 5.56) none fire/all fire spec is 12-60 in/ozs. and cup thickness for both 41 and 450 is .025". Two different rifles and two different cartridges.

You are very good at not providing the sources of your information, but I believe you found your Carbine primer sensitivity data from this:

The Gun Zone: The 5.56 X 45mm: 1963-1964
http://www.thegunzone.com/556dw-2.html

At Frankford Arsenal, William C. Davis issues "First Memo Report on AR-15 Rifle Ammunition Systems: Investigation of Firing Pin Energy and Primer Sensitivity." The kinetic energy of the existing AR-15 firing pin is found to range from 4 to 14 inch-ounces when the bolt closes. While Frankford does not currently have equipment to determine the sensitivity limits of .223 primers, they have been told by Remington that it should be comparable to military .30 Carbine primers. Primers for military .30 Carbine cartridges have "None Fire/All Fire" tolerances of 6 to 36 inch-ounces. Davis recommends that the None Fire limit for .223 ammunition should exceed 15 inch-ounces.

Frankford personnel submit study to TCC regarding primer sensitivity level versus risk of slam-fires:

None Fire - All Fire limits Risk of Slam-Fire
16-64 in-oz 1 In 10 million
12-60 in-oz (Current sensitivity limit for 7.62mm NATO) 1 in 160
12-48 in-oz 1 in 6,400
14-56 in-oz 1 in 11,000

From this report, “Report of the M16 Rifle Review Panel. Volume 5, Appendix 4. Ammunition Development Program “ www.dtic.mil/dtic/tr/fulltext/u2/a953114.pdf

The #41 primer sensitivity limits were set as none fire, 12 inch ounces, and all fire, 48 inch ounces.

What I have been using for primer comparison is Mil P 46610E, Primers, percussion, Styphnate and Chlorate Types, for Small Arms ammunition. This spec dates to 1973. For the M1 Carbine the all fire (H + 5 sigma) and none fire limits (H-2sigma) are 18 inches and 2.5 inches. For the 5.56 primer, the all fire limits (H + 3sigma) and none fire limits (H-3sigma) are 12 inches and three inches. As we all know, H is the average ignition height of the primer. I would infer from this that the Carbine primer is less sensitive than the 5.56 primer .

If the energy numbers you have given are correct, then the 5.56 primer is less sensitive than the carbine primer. The chance of an inbattery or out of battery would in fact, be less, if the #41 primer was used.

Maybe you can reconcile the difference between these references. It would be helpful if you found the all fire and non fire limits for commercial small rifle primers because the data we are using is for “mil spec” primers. I don’t know any source for the kinetic impact energy of the M1 carbine firing pin. Do you have this? If you notice, the AR15 firing pin impact energy was something that William Davis had and used in deciding primer sensitivity for the AR15. He also used it to determine probably of a slamfire, given the varience in primer sensitivities.

If commercial rifle primers are less sensitive than mil spec M1 carbine primers, than I would consider them acceptable for use in the carbine. However, this does not mean slamfire risk is zero, as primer sensitivity varies, and as the examples I have posted shows, there are overly sensitive primers in factory ammunition.

As for your CMP reference, I have volunteered at the CMP. The guys there tend to be enthusiasts, (for some it is just a job), but I do not consider the CMP an authority in ballistics or primer sensitivity. The CMP is an organization that receives old American surplus weapons and sells them to eager shooters and collectors. They neither design or manufacture anything, the only engineers I ever met were volunteers trying to pluck out choice pieces for their collections. Their use of a WSR primer does not mean they studied or understand primer sensitivity.

 

[345 DeSoto]

GATORWADE - Cut through all the crap here and use what Hodgdon and/or Lyman recommend...

 

[USSR]

Good point 345 DeSoto. Lyman recommends the Remington #6 1/2 (a standard small rifle primer), and check out what primer Remington uses in their loaded ammo: "30 Carbine. L30CR1. 110 UMC® Metal Case. 6 1/2. 1990 1567 1236 1035 ...", even though they also make the Remington #7 1/2 small rifle primer which has a 25% thicker cup.

Don

 

[gatorwade]

Hoo...Ahh! Post a question on this forum and you don't get a primer on the subject, you get a thorough schooling. Thanks, ya'll, for so generously sharing your depth of knowledge and experience, +P. Very helpful to myself and man others, no doubt.
Confident with new understanding, I beat it down to my LGS, Huntington's in Oroville. Lo, the primer shelf was full. Left with a bunch of CCI 400's. At 2014 prices, but that's better than not having enough components for whatever may come. Alas, the shelf where the H110, and the Sierra bullets shelf remained empty. As they have remained since we all got nervous about the intentions of the PTB. But I am still GTG.
I'll save the 41's for the 6.8 SPC. But might I add, that I loaded 700 rounds for the Stag 7 and fired them with no problems and excellent groups, before switching to 41`s when they came available.
Now gotta go and trim some brass just right and see what happens. If I had a new barrel on my 71 year old Underwood, and some fresh eyes, I might learn something about the potential of this fun rifle.

 

[gatorwade]

Ooops. Forgot to add that the first 700 rounds of 6.8 were with Winchester WSR primers. No slamfires...yet...

 

[Slamfire]

Maybe you can reconcile the difference between these references.

Well I figured it out. It has to do with the number 2 and the number 4. After calculating Kinetic Energy with the number 2, and then with the number 4 , the reasons for the differences in impact energy become obvious.