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45acp small vs. large primers?


jstagn

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1.249. Usually I'd go a little longer in my gun, but a friends has a slightly shorter chamber dimension and I sometimes load a few for him. 1.250 has usually been the standard length for H&G 68 molds or copies. Some others have a slightly different shape.

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It really depends on brand as well as size. I find that with CCI SP/LP, there is a drop in velocity (around 20fps drop in the avgs, IIRC) with my loads. I get about the same velocity from 230gr jacketed bullets with 4.5gr WST and LP or 4.7gr WST and SP.

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There was a very extensive study done by a guy over on Snipershide across 4 different powders, multiple temps, and several Bullet weights. He found no difference at low to midrange charges but every powder dropped off in velocity at the upper end of the powder range. The prevailing theory was that the small primer doesn't ignite large amounts of powder in the same manner as large.

I see no difference but my loads are all low to midrange.

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Was he using rifle primers or pistol primers (in the small varieties) ???

Small Pistol. I know rifle primers tend to be harder but are they supposed to burn hotter or differently than pistol?

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The person who came up with SPP for the .45 ACP should rot in Hell for eternity.

Embrace the suck. I've sold all my LP .45 and bought SP .45. Now I don't have to change the primer system on my 650 to load 9mm, .40 and .45.

I hated it too and threw away brass everytime I found it. But they keep making it.

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Seriously though I have loaded A lot of bot SP and LP .45 and I have used SP,SPM,SR, LP,LPM primers in both 4.3 to 4.4 grains of Clays has made major for me at a couple of USPSA, Area 7 matches. I have found much more variation in velocity and pressure with different Bullets, OAL's, Crimps, temperatures, humidity's, than I have noticed changing primers.

That is why we work up a load and test it under different conditions. I personally like the SP .45 these days because no one seems to want it. The LEO's that shoot .45 leave it on the ground by the bucket full, most of it has a crimped primer so you know that you are getting actual once fired at a glance. I find that the flash hole is bigger, and I think this offsets some of the burn difference. YMMV

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The magnum SRPs are supposed to be hotter, don't have any way to really tell about that. I know that in the Tulas the KVB-223 is supposed to have a thinner cup - 0.023 vs 0.025 - than the other two.

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Load both

Same loads in both and they chrono the same in my guns, both revo's and auto's

I use the sp brass for my 625 so I don't leave any on the range to upset y'all

just PM me and you can send all that dreaded sp bras to me and I'll share some of it with Steve RA. LOL!!!!!

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