Large pistol magnum OK for 45 acp?

mustang66maniac · May 28, 2009, 11:46 PM

So my uncle hooked me up with some old Winchester primers. They say "large (mag.) pistol primers" on the box. Can I use these for 45 acp reloading? This all came to me as a birthday present. Thanks.

tiberius10721 · May 29, 2009, 12:52 AM

no you cant use them youll have to send them to me.

Just kidding they will be fine but you will have to start at minimum powder charge and work your way up if u use magnum primers.Ive used magnum primers for 45 acp and never had a problem.

bobotech · May 29, 2009, 01:48 AM

I have been using mag primers almost exclusively due to the fact that I ended up with a large amount of small and large pistol mag primers.

They all work just dandy and fine if you use starting loads and work up. Don't start at the mid range or use your already established hot loads, start up from only starting loads.

mustang66maniac · May 29, 2009, 08:04 PM

Thanks guys.

mustang66maniac · June 6, 2009, 06:25 PM

Ok, so I started loading up some ammo with 4.5gr of Hodgdon Universal and a 230gr LRN. Ill let you guys know what I find with these loads.

Ozzieman · June 7, 2009, 06:37 PM

This question comes up so often that I did some testing with small standard vs mag.
I would say no, use what the manufacture recommends. A mag primer can has so much more energy that it can actually move the bullet before the powder has time to fully ignite. Then once it ignites it will act like your OAL is to long causing lower pressure firings.
Sounds hard to believe, but that seems to be what happened.
I also tried another little experiment using primers and plastic shot caps in a 38 with out the shot and without powder.
I was surprised how more energy a mag primer has than a standard.
You might not have any problems but try the same thing that I did. What ever load you start at try a couple with standard and a couple with Mag and see what difference you get.

http://thefiringline.com/forums/showthread.php?t=349807

kraigwy · June 7, 2009, 06:54 PM

Use them:

I called CCI, Remington and Winchester about this same subject (only in Small Pistol). The average recomendation was that the load should be reduced 5% to get the same results.

I'd back up a tad on the powder charge. If you have a crony, back off on the powder, then adjust until you get the same velocity your load got with the non mag. LP primers.

Personaly I dont care what the velocity is on my 45s. I want accuracy and reliability.

mustang66maniac · June 7, 2009, 07:09 PM

Hey Ozzieman, I actually read your thread before I decided to load these up, and interestingly enough, i had very similar results. I loaded up a box of these and brought and box of factory 230gr fmj to compare it to at the range. The difference was pretty big. The reloads felt really weak, it felt like it barely cycled the action. Now granted, I started at the low end of the spectrum which only was supposed to have 11,400 CUP and 700 fps, but i didn't know i would be able to see that big of a difference. I also noticed it was very smokey and dirty. Now, I don't know if it was like this because the load was weak or because the magnum primer pushed the bullet out before the powder got a chance to ignite.

I think next time i'll take a step up in the powder load and see if it makes a difference. Im still waiting on large pistol primers on backorder from cabelas.

**Unclenick** · June 7, 2009, 07:22 PM

Winchester large pistol primers are a funny exception. They are unique among LP primers (AFAIK) in that Winchester makes just the one primer for both standard and magnum loads for large pistol (they make separate magnum and standard primers for small pistol). I have run the WLP in target loads in .45 ACP and never had a problem. A number of the guys in our old bullseye league used nothing else.

Magnum priming ignition can be managed by more than one means. One is just a larger charge of priming mix which make for more pressure. Another is using more fuel and less impact sensitive material, which results in a mix with lower brissance and longer flame duration. You just have to try a primer out to be sure what it is going to do? It is always wise, however, to assume it will raise pressure and work loads back up from 5% below your established load.

The soot is likely to be due to low pressure. Increasing the charge will help. Another thing that can help is to go to an even faster powder for the light loads; Clays, Solo 1000, N310. Most powders won't burn cleanly at very low pressures. An exception seems to be IMR Trail Boss, which seems to be clean at all pressures. It is only for cast and swaged lead bullets, though, and not for jacketed bullets.

May 28, 2009, 11:46 PM	#1
mustang66maniac Senior Member Join Date: March 2, 2008 Location: Sac, CA Posts: 143	Large pistol magnum OK for 45 acp? So my uncle hooked me up with some old Winchester primers. They say "large (mag.) pistol primers" on the box. Can I use these for 45 acp reloading? This all came to me as a birthday present. Thanks. __________________ "aerodynamics are for people who can't build engines" -Enzo Ferrari

May 29, 2009, 08:04 PM	#4
mustang66maniac Senior Member Join Date: March 2, 2008 Location: Sac, CA Posts: 143	Thanks guys. __________________ "aerodynamics are for people who can't build engines" -Enzo Ferrari

June 6, 2009, 06:25 PM	#5
mustang66maniac Senior Member Join Date: March 2, 2008 Location: Sac, CA Posts: 143	Ok, so I started loading up some ammo with 4.5gr of Hodgdon Universal and a 230gr LRN. Ill let you guys know what I find with these loads. __________________ "aerodynamics are for people who can't build engines" -Enzo Ferrari

June 7, 2009, 06:54 PM	#7
kraigwy Senior Member Join Date: June 16, 2008 Location: Wyoming Posts: 11,061	Use them: I called CCI, Remington and Winchester about this same subject (only in Small Pistol). The average recomendation was that the load should be reduced 5% to get the same results. I'd back up a tad on the powder charge. If you have a crony, back off on the powder, then adjust until you get the same velocity your load got with the non mag. LP primers. Personaly I dont care what the velocity is on my 45s. I want accuracy and reliability. __________________ Kraig Stuart CPT USAR Ret USAMU Sniper School Distinguished Rifle Badge 1071

June 7, 2009, 07:09 PM	#8
mustang66maniac Senior Member Join Date: March 2, 2008 Location: Sac, CA Posts: 143	Hey Ozzieman, I actually read your thread before I decided to load these up, and interestingly enough, i had very similar results. I loaded up a box of these and brought and box of factory 230gr fmj to compare it to at the range. The difference was pretty big. The reloads felt really weak, it felt like it barely cycled the action. Now granted, I started at the low end of the spectrum which only was supposed to have 11,400 CUP and 700 fps, but i didn't know i would be able to see that big of a difference. I also noticed it was very smokey and dirty. Now, I don't know if it was like this because the load was weak or because the magnum primer pushed the bullet out before the powder got a chance to ignite. I think next time i'll take a step up in the powder load and see if it makes a difference. Im still waiting on large pistol primers on backorder from cabelas. __________________ "aerodynamics are for people who can't build engines" -Enzo Ferrari

May 29, 2009, 12:52 AM	#2
tiberius10721 Junior member Join Date: December 22, 2008 Posts: 228	no you cant use them youll have to send them to me. Just kidding they will be fine but you will have to start at minimum powder charge and work your way up if u use magnum primers.Ive used magnum primers for 45 acp and never had a problem.

May 29, 2009, 01:48 AM	#3
bobotech Member Join Date: February 22, 2008 Posts: 60	I have been using mag primers almost exclusively due to the fact that I ended up with a large amount of small and large pistol mag primers. They all work just dandy and fine if you use starting loads and work up. Don't start at the mid range or use your already established hot loads, start up from only starting loads.

June 7, 2009, 06:37 PM	#6
Ozzieman Senior Member Join Date: December 14, 2004 Location: Northern Indiana Posts: 6,117	This question comes up so often that I did some testing with small standard vs mag. I would say no, use what the manufacture recommends. A mag primer can has so much more energy that it can actually move the bullet before the powder has time to fully ignite. Then once it ignites it will act like your OAL is to long causing lower pressure firings. Sounds hard to believe, but that seems to be what happened. I also tried another little experiment using primers and plastic shot caps in a 38 with out the shot and without powder. I was surprised how more energy a mag primer has than a standard. You might not have any problems but try the same thing that I did. What ever load you start at try a couple with standard and a couple with Mag and see what difference you get. http://thefiringline.com/forums/showthread.php?t=349807

June 7, 2009, 07:22 PM	#9
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,061	Winchester large pistol primers are a funny exception. They are unique among LP primers (AFAIK) in that Winchester makes just the one primer for both standard and magnum loads for large pistol (they make separate magnum and standard primers for small pistol). I have run the WLP in target loads in .45 ACP and never had a problem. A number of the guys in our old bullseye league used nothing else. Magnum priming ignition can be managed by more than one means. One is just a larger charge of priming mix which make for more pressure. Another is using more fuel and less impact sensitive material, which results in a mix with lower brissance and longer flame duration. You just have to try a primer out to be sure what it is going to do? It is always wise, however, to assume it will raise pressure and work loads back up from 5% below your established load. The soot is likely to be due to low pressure. Increasing the charge will help. Another thing that can help is to go to an even faster powder for the light loads; Clays, Solo 1000, N310. Most powders won't burn cleanly at very low pressures. An exception seems to be IMR Trail Boss, which seems to be clean at all pressures. It is only for cast and swaged lead bullets, though, and not for jacketed bullets. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle Last edited by Unclenick; June 7, 2009 at 07:28 PM.