SIGforum
Question about large pistol and large rifle primers.

This topic can be found at:
https://sigforum.com/eve/forums/a/tpc/f/840601935/m/2550001705

March 02, 2024, 02:00 PM
apf383
Question about large pistol and large rifle primers.
So, feeling sick earlier in the week I took a day off from work. Decided to catch up on some reloading. Loading .45ACP I mistakenly used lrp’s instead of lpp’s. Didn’t realize it until I grabbed the next box of primers, so I’ve got 100 rounds that I’m definitely not pulling apart. My loads were to replicate factory power so 5.8gr. of Unique pushing Precision Delta 230gr. FMJ projectiles. Not over-powered by any means and clocking about 800fps (per manual, I don’t chrono my loads). So here’s the question. Do I run them through my pistol or play it safe and run them through a 45 caliber carbine? Thanks guys.



Foster's, Australian for Bud

March 02, 2024, 04:21 PM
sourdough44
I don’t have a lot of advice on the subject, just some comments.

I’ve done limited testing with the SR/SP substitutions, never had a problem. As usual, safety concerns are less if a load isn’t near max, usually.

I didn’t look up the load, you say it’s not near max. If so, less of a concern.

As you are likely aware, LR primers are taller than LP. That alone ‘likely’ won’t cause problems.

If it was me, I’d take my rifle, have safety glasses on and test some.
March 02, 2024, 04:48 PM
GT-40DOC
Check real close and be sure that those LRP are not seated too high to work correctly.
March 03, 2024, 08:28 AM
apf383
I’m reloading for a match in May, and I did notice quite a few seemed to not be deep enough. I’ll save them for rang fun as I need to be able to count on them for a match. Thanks guys.



Foster's, Australian for Bud

March 03, 2024, 09:32 AM
Riley
I’d chrono one through the carbine to see where it’s at compared to pistol.

To things to be aware of. One, is the height causing malfunction or if they’re really high, a slam fire condition. Not like but possible.

The other is, at least in small rifle primers, the cup is harder and a pistol may not set them off. We tried CCI small rifle and in the striker guns we had available, they wouldn’t fire. I had to put in a heavier main spring in the hammer guns to get them to fire. They wouldn’t fire with competition springs.




Do not send me to a heaven where there are no dogs.
Step Up or Stand Aside: Support the Troops !
Expectations are premeditated disappointments.
March 06, 2024, 10:13 PM
MikeinNC
I know the large pistol primers are softer than large rifle primers. I use blown out rifle brass for my 410 shogun and my gun won’t set off LRP in the brass but work fine with the LPP.

With the low pressure of the 45ACP I wouldn’t stress, but I’d try a few cases with just the LRP thru the gun to see if it will set them off.



"Violence, naked force, has settled more issues in history than has any other factor.” Robert A. Heinlein

“You may beat me, but you will never win.” sigmonkey-2020

“A single round of buckshot to the torso almost always results in an immediate change of behavior.” Chris Baker
March 07, 2024, 06:16 AM
apf383
Sounds good guys. Thanks.



Foster's, Australian for Bud

March 10, 2024, 03:14 PM
jsjac
Here is a chart of primer cup sizes.

https://www.sierrabullets.com/primer-substitutions/
March 10, 2024, 08:06 PM
apf383
Thanks Js.



Foster's, Australian for Bud

March 11, 2024, 04:30 AM
Jim Watson
I gave it a try on a FEW rounds.
My Dillon 1050 would drive LPs flush in .45 ACP pockets.
My 1911 fired them all.

Not knowing just what pistol and carbine you have, I can't say which or whether would be safer and more reliable.
March 14, 2024, 05:39 PM
apf383
Hi Jim, a few 1911's and Sigs, carbine can more than handle it as well, I'm certain. Thanks.



Foster's, Australian for Bud

March 15, 2024, 08:48 AM
pbslinger
quote:
Originally posted by jsjac:
Here is a chart of primer cup sizes.

https://www.sierrabullets.com/primer-substitutions/


From this chart, the height of a LPP is .115 - .126, and a LRP is .123 - .136. The height tolerances overlap, so depending on the particular LRP, it may not protrude beyond the case. So while I would have thought the main issue would be the increased height of the LRP being the problem with using them in Large Pistol cases, but primer hardness and power could be more important factors.

A reloading rule is to work up loads whenever any component is changed, and this is about as dramatic change in primers as is possible.