Stocking only magnum pistol primers?

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I use magnum primers with ball powder because that was the thinking when I started reloading. I have never experienced a problem doing this and I shoot full-house loads for my .45 (Ruger) Colt with 2400 plus .44mag with H110/296. I do have a couple thousand CCI 550 S.P. primers left that I use for plinking rounds to use them up.
 
That's not a good idea if you load for small volume rounds like 9mm, 380, 40 ..... A lot of times these primers are so explosive that they will dislodge the bullet before the pressure builds.
Thanks for the tip, I'll keep it in mind when I start loading for autopistol. Has this been known to happen in revolver cartridges?

It's a great line of thinking until you find that you have a finicky gun. The real question is: Have you tested SPM loads in your guns for accuracy and function? I'm not saying don't buy SPM's if you find a great deal. I'm still working off my pres#44 SPM's when I couldn't get SPP's. That said, I learned the hard way and have some reloaded SPM primered ammo that works great in some guns, but won't fire 100% in other guns. Just make sure to test before you purchase in quantity.
Yep, I get consistent ignition in all my guns.

Found it:
According to Pearce: “In magnum revolver cartridges, such as the .357, .41 and .44, the powder should be determined before selecting a primer. This is important, as many magnum revolver cartridge powders perform better when ignited with a Standard primer rather than a Magnum primer. This has been proven in several ballistic labs, not to mention my own testing and experience. In one lab test, .44 Magnum loads containing 2400 increased 11,000 psi when capped with a CCI 350 magnum primer versus the same charge capped with a CCI 300 standard primer. As a result, the powder charge must be reduced to stay within SAAMI pressure guidelines, which likewise reduces velocity."
Sometimes this slips by the reloading manual people. A good example is the 1994 #12 Speer manual where CCI magnum primers were used in 2400 data. When Pearce told Speer's Allan Jones about this, at first he was skeptical. Then he re-shot the 2400 data using standard primers and confirmed Pearce's claim was correct. The data was corrected in the #13 manual with the significantly better performance of the standard primer published.
Thanks, that's interesting. So I may be looking at a velocity loss by using a SPM in, say a 38 special load where standard primer is specified. Is there a way to quantify this loss?

The other question is, let's say I'm loading 4.5gr HP38 under 158gr SWC in a standard 38 load. If I sub a mag primer, I'll usually back off .2 grain or so to compensate. Leaving aside performance/velocity issues, is there a safety reason not to make this common practice?
 
Lane Pearce of Shooting Times? If correct, Which issue?

"It has been brought out by Dave Scovill, editor of Handloader magazine, and one of its earlier contributors, the late Bob Hagel, that certain primers work well better with certain powders. Hagel did a large body of research on this subject in 1982, and Scovill has done some follow-up checking and research. In addition, Brian Pearce has done a lot of work with handguns and has some opinions that collaborate what the other two have found in their research.
Hagel's 1982 article is available online at this link: "Primers for Magnum Handguns". Info by Scovill and Pearce is found in the October and December 2011 issues of Handloader magazine."
 
I love the Win WSPM for most loads in 357, nice and hot, but with fast flake powders and light target 38 loads I really like a non-mag primer.
 
Good question, and I do not know the answer, but I do know that new 2400 and regular SP primers shoots great, haven't tried SP mag primers though, don't have any.
I did load 20x rounds of .357 Magnum with the new 2400 and both standard and magnum CCI primers. I didn't bring my chrono that day. I shot them off a bench and rest to check accuracy from a 4" M686. The standard primers ammo was noticeably more accurate which made me regret not having the chronograph with me. Of course this was with my gun only.
 
I did load 20x rounds of .357 Magnum with the new 2400 and both standard and magnum CCI primers. I didn't bring my chrono that day. I shot them off a bench and rest to check accuracy from a 4" M686. The standard primers ammo was noticeably more accurate which made me regret not having the chronograph with me. Of course this was with my gun only.
I find that extremely interesting. Please don't take my statement as doubting your results by any means. By interesting, in my testing with magnum vs standard SPP I have found about 25fps to be the difference on average depending on powder and load. I would never think that 25fps would have any noticeable affect on accuracy. I wish you did have your chronograph with you because I'm betting to see a difference in accuracy, you are getting more of a variance in velocity than I have seen.
 
I find that extremely interesting. Please don't take my statement as doubting your results by any means. By interesting, in my testing with magnum vs standard SPP I have found about 25fps to be the difference on average depending on powder and load. I would never think that 25fps would have any noticeable affect on accuracy. I wish you did have your chronograph with you because I'm betting to see a difference in accuracy, you are getting more of a variance in velocity than I have seen.
I don't think the velocity was the cause. 2400 is a very old powder and my guess, and only my guess is the hotter primer changes the way the powder ignites effecting the pressure curve and in turn effecting the accuracy. To a lesser extent I see the same results with Unique.
 
I don't think the velocity was the cause. 2400 is a very old powder and my guess, and only my guess is the hotter primer changes the way the powder ignites effecting the pressure curve and in turn effecting the accuracy. To a lesser extent I see the same results with Unique.
That would make some sense. Makes me think of an ongoing discussion I've been having with a buddy for several months and we've never actually tested, but would 2 bullets fired from the same gun with the exact same velocity give equal accuracy with the only variable being 2 different powders? He thinks that since 2 different powders would almost have to have different pressures even though they are giving the same velocity would affect the accuracy. I don't agree. My thinking is that 2 identical bullets traveling the same velocity would have to give the same accuracy no matter how they achieved the velocity.
 
I use Trail Boss for mild 357 loads for my Winchester. Hodgdon's load data says to use small pistol magnum primers with that powder,so I do. Might be because of the large volume case fills with TB.
 
That would make some sense. Makes me think of an ongoing discussion I've been having with a buddy for several months and we've never actually tested, but would 2 bullets fired from the same gun with the exact same velocity give equal accuracy with the only variable being 2 different powders? He thinks that since 2 different powders would almost have to have different pressures even though they are giving the same velocity would affect the accuracy. I don't agree. My thinking is that 2 identical bullets traveling the same velocity would have to give the same accuracy no matter how they achieved the velocity.
In a rifle, the “barrel time” could be different, even for the same velocity. (Think of two dragsters with the same speed at the finish linet but with different elapsed times.) With barrel whip and harmonics, exactly when the bullet leaves the barrel becomes more important than the velocity, and different powders with different burn rates and pressure curves will affect that.
 
In a rifle, the “barrel time” could be different, even for the same velocity. (Think of two dragsters with the same speed at the finish linet but with different elapsed times.) With barrel whip and harmonics, exactly when the bullet leaves the barrel becomes more important than the velocity, and different powders with different burn rates and pressure curves will affect that.
I could certainly see the merit in a rifle barrel with the whip and harmonics, but in a revolver? I would think the whip if any in a revolver or automatic barrel would be so small it wouldn't make any difference or at least any noticeable difference. It wouldn't be that hard to test with a Ranson Rest. The hard part would be finding 2 powders that would give the same velocity. If the whip and harmonic theory is correct, I would then guess the barrel length would play a major factor. Probably more so in a rifle than handgun. This is one of those time where I'm catching myself way overthinking something!
 
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I wonder what the results would be at 14.5 Grs 2400.

For me, 2400 settled down and shot much better when I went from 14.0 to 14.5 Grs under a 158 Gr coated SWC.
 
I prefer magnum in all cases. Pressure is driven by a combination of powder and primer, right? So as a philosophy if you watch your pressure to achieve safe loads at all times, wouldn't an increase in primer power ensure greater powder combustion and reliable ignition, versus the same pressure but less ignition?

I'm all magnum based on that thought process.
 
H2400 = Hercules 2400 manufactured in ’92.
A2400 = Alliant 2400 of current manufacture (purchased 2 months ago)

The newer powder produced higher pressure. Add the mag prime and its over SAAMI 35,000 PSI pressure. Edit add 35,000 PSI

Years ago i started with 14 grs , mag primer. Now loading 13 grs with a (158) 163 gr lswc plain base. Powder lot makes a difference, old vs new. Link is proof to me.
 
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I do this to an extent. Im not positive but im under the impression that the main difference between standard and magnum primers is the thickness/hardness. Ive never really noticed a difference in velocity, point of impact , recoil or report from using magnum primers. I run through a lot of h110/296 and always use mag primers for that. But even in my 45-70 i use large mag rifle primers just because of the volume of powder and the potential for cold weather use. Ive used cci #41 (military smr primer) for 454 casull with no problem too. If the firing pin has the force set off the primer ive never found a reason not to use them

I should add, i mainly load magnum type cartridges 357, 44 mag, 454 casull, 338 lapua, 45-70 (which is often loaded light but sometime heavy) and 30-30 (which i never load hot, but do often use standard lr primers just cause i got 1000 for cheap and havent worked through them yet)
--- of course always use published load data from a reliable source and if you choose to do otherwise blame no one but yourself if it goes bad---
 
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The newer powder produced higher pressure. Add the mag prime and it over SAAMI pressure.

Years ago i started with 14 grs , mag primer. Now loading 13 grs with a (158) 163 gr lswc plain base. Powder lot makes a difference, old vs new. Link is proof to me.

I read the article and it was very interesting. I see a huge difference in the pressures, but one thing that caught my attention, was depending on whos data you look at, only one of the loads he listed and I think it was with the Winchester primer was over the max pressure that is listed by Hodgdon. The newest Hodgdon data list the max load of 158gr XTP is 16.7gr of H110 with a pressure of 40,700. All of the other loads he posted are under the max pressure stated by Hodgdon. While I use magnum primers in all my loads, I'm very careful about working up to max and almost never use max powder charges listed.
At the end of last summer and into the fall, I was doing some unscientific testing on primers and my testing was magnum vs standard primers for target loads. What I was testing was difference in consistent velocities as well as accuracy. No of my loads were anywhere near max, so pressure was not a concern. all were with 38 special and only a few were approaching +P range. Then my chronograph was stolen and I have not had enough time to shoot much so I haven't replaced it. Here is what I did find before stopping. The majority of my target shooting consists of 3 Powders. Bullseye, Universal and HS-6. I only use Federal Primers since some of my revolvers have very light actions and CCI will not ignite 100%.
Here is what I did find.
One disclaimer. Accuracy was me shooting off a rest. I'm sure off a Ransom Rest it would be more scientific, but I don't have one. I'm certainly not an expert marksman, but can hold my own with a Revolver.

Bullseye.
Using the sold stand by load of 3.0 gr. with 148gr swaged HBWC and also 158gr SWC both regular lead and HyTek Coated.
No noticeable difference in accuracy from standard to magnum. Accuracy with Bullseye Loads was at 15 and 25 yards.
Magnum primers did give a slight edge in more consistent velocities (less of a spread with magnum) but only slightly better.

HS-6
Tested Several Different bullet weights and charges. 130gr HyTek Coated, 158gr SWC Lead and Coated and 158gr FP Coated.
These were tested at 25 and 75 yards for Accuracy.
Magnum Primers preformed much better with HS-6 no matter how light or heavy I went with powder charge.
A bid difference is velocity spread. Magnum Primers had much less spread than standard in all loads I tried.
Accuracy was about the same with either primer at 25 yards. Close enough to call even.
AT 75 yards, the accuracy was much better with magnum primers. Of course you would expect that result with the velocities being more consistent.

Universal
I use more Universal than any other Powder, so I spent a little more time here.
Tested bullet weights were 148gr HBWC, 130gr Coated FP, 158gr SWC Coated and Uncoated, Berrys 158gr THP, and Speer 158gr FMJ Plinker
Results were much like HS-6 but not as noticeable of a difference from magnum to standard. Sort of in between
Again, accuracy at 25 yards was a toss up but accuracy at 75 was noticeably better with magnum primers.

My testing may not help anyone and/or change the way you do things on your bench. I know what was posted above was more of a comparison on pressures for safety purposes which I'm all about. My testing was really about accuracy and consistency which really go hand in hand.
I think one of the problem with a lot of reloaders out there today is trying to push everything to the max and this is what causes people to get hurt. The data posted above about pressures did certainly open my eyes. Most of us veteran loaders by now have worked up there standard loads that have worked for years and at least for me, the quest is to squeeze out a little more accuracy not fps. If I want something hotter than .357mag, then I go to the 41 or 44 mags. No sense in being unsafe just for a little more power.
My conclusion to my testing is that I will continue to use magnum primers for everything since I see a tad more accuracy. It also may have been a little bias testing since I have about 30k Federal Magnum SPP on hand. Any comments favorable or critical will be appreciated.
 
I realize this is a bit apples vs oranges, but...

I've always used H335 in the 5.56mm, because H335 is a ball powder some data suggests a magnum primer with it. I did an informal test with a generic load of H335 and a 55grn bullet, out of my 20" barreled Colt H-bar. What I found was... the standard primers not only gave higher average velocity, but lower SD than the magnum primers. I did not check it for accuracy, but what that does tell me is there is a tangible difference. In those cases where a magnum primer might be specified, if I'm working up a load for accuracy, I will load some with either or to see if it does make a difference in that particular load. No, I don't do it with powders like Unique, and I don't deviate from a magnum primer with powders like H296. I also did the same type work up with IMR4227 in the .41 Magnum... I had some question about using a magnum primer there, it seems the internet consensus is split about 50/50 on it. I found, with a 20grn charge of IMR4227 under a cast 215grn bullet, fired from my 20" Marlin, the CCI standard primers had lower SD than the WLP (standard or magnum, as advertised,) and the Federal magnum primer... all else being equal. I acknowledge that going up or down 1-2grn of powder might change that equation... you never know... which is why I don't typically make blanket standards for reloading.
 
I've always used both. It takes a little bit more room in my primer storage area but it hasn't created a problem for me but do what makes you happy.
 
Magnum pistol primers have more compound to better ignite large charges and or powders that are hard to ignite, like some ball powders.

No way I would use mag primers only, but some people do because it makes it easier. Not a great reason IMHO.
 
Just a couple of points.

Hodgdon data for the 357 Mag is in CUP and Larry GIbson's data (link posted above) is in PSI. Don't remember the exact CUP max, but IIRC (no guarantee), it's 42K while current PSI max is 35K. http://saami.org/specifications_and_information/publications/download/205.pdf

Larry Gibson did another study using the .44 mag comparing "Old" Herc and "New" Alliant 2400 == also on the cast bullet forum:

http://castboolits.gunloads.com/showthread.php?72355-B-2400-Hercules-vs-Alliant-B&highlight=2400

Shows actual results (pressure/velocity) using the 429421 and 20.5, 21.0, 21.5, and 22.0gr of Old H2400 and new Alliant 2400. If you scroll down past the verbiage (about 1/4 to 1/3 down the page), you can see the results. He was using an Oehler (SP?) unit that measures pressure.

Primers can make a difference (pressure & accuracy), possibly to a significant degree, depending on the powder/powder charge being used and an individaul gun's preference. I'm sure powder lot variations also enter into the equation.

FWIW,

Paul
 
For small pistol, many people, including myself, have used small rifle primers with no issues providing that your pistol can light them off. IE, I use CCI 400s in 9mm and small primer 45 ACP with no issues. Ive used the CCI 400 for loads as light as 3.1gr of TiteGroup in 9mm and as high as 8.3gr of CFE Pistol in 45 ACP with no issues. I also use CCI 400s in 223 with some pretty stout loads with no issues. I also know plenty of guys that are shooting small primered 6.5 and 308 with CCI 400s with no issues.

Its nice being able to just simplify my primer purchasing being all my small primers are all the same now.
 
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