Large Magnum Pistol Primers in 45 acp?

Bazoo said:

Titegroup and the Lyman 452374 data will likely result in tight-groups.

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1KPerDay said:

You talking about the bullets or the powder? If you have data for 230 gr FMJ or LRN use either and you’ll be fine.

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Bazoo said:

Open your Lyman manual to the 45 auto section. Look at the cast bullets. Lyman bullet number 452374. It’s the classic round nose 225 grain cast bullet. It duplicates factory ball with a cast bullet.

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Bazoo said:

I have used small primer 45 brass as substitution for large primered without any issue. I’ve researched it and what I’ve found is the people that’s tested it more extensively have shown it to be safe as far as pressure (meaning, using small primer brass isn’t going to up the pressure with an already proven large primer developed load). Generally no change to a better change in consistency of ignition.

For the mag primers, If you only have a pad of mag primers to use up, after you have a load developed with your main primers, then reduce your powder charge 5% and substitute your mag primers. Or save them till you have enough to be worth developing a specific load for.

Here is how I develop a 45 auto load.
The Lyman 49th says

45 auto

452374 bullet @ 1.272 OAL (make sure to test the length, that it fits your gun. If you have to reduce oal by .005 that’s fine, but if you have to reduce it .020 you may need to reduce the starting charge slightly)

4.5 titegroup to 5.1

I’d load 5 each with
4.5
4.6
4.7
4.8

Then I’d shoot them on paper, for groups. Each at a different target. See how they group. Maybe the 4.8 will group great but the 4.5 won’t. Provided they all feel normal as to recoil, and ejection is normal, as in, not excessively farther than normal and to the same direction as normal, I’d load the rest with the most accurate powder charge.

But regardless of accuracy, if that 4.8 recoils harder than normal, or throws the empties 15 feet instead of 6 (whatever normal for your gun is), then I would use a lower powder charge. Recoil of the gun and ejection is really your only clue as to pressure (unless you have a chronograph) on a low pressure round like 45 automatic.

If the 4.7 feels and looks good, load 25 or so and test farther. If that goes good, load the rest.

Would I load 4.9, 5.0, 5.1? Maybe... if the lighter charges seemed under powered. But probably won’t be any need. Likely the 4.6-4.8 will feel and perform like factory ammo. Would the 5.1 be over pressure? Maybe, probably not, but it might be right at the limit. You can’t tell, and neither could I. But it’s better to have a little safety bumper zone since you're substituting bullets and primers and you’re loading techniques and components are different than the testers at Lyman had.

The goal isn’t to load at the pressure limit for your cartridge, but make accurate and reliable ammo under the limit.

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