Forty-Fives: .451 vs. .452?


December 11, 2003, 09:58 AM
I bought some magazine recently that has a Hornady poster showing all (or at least some) of their bullets. I have never had a 45 of any kind and have never done reloading myself, so I have no reason to know: for the ".45 caliber", it shows three bullets in .451 in one group, and four others in .452 in another group. The .451's have no cannelure but all the .452's do, and the .451's are all lighter--matter of factly, the heaviest .451 is 230 gr and the lightest .452 is 240 gr. What guns are these different bullets for? What happens if you fire each from the other's gun? Is there a dramatic rise in pressure from the bullet that's "too big"? A noticeable loss of accuracy or velocity from the bullet that's "too small"?
Am not considering any "experiments", mind you, just wondering....

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December 11, 2003, 10:05 AM
That is an interesting theory. I have always considered that the "nominal" dimension (.357, .429,.451 etc.) are what jacketed bullets are made and .001 or .002 over nominal are what the lead (alloy) bullets are made. Quantrill

December 11, 2003, 10:13 AM
Possibly the .452 jacketed bullets are for .45 colt/.454 Casull? Most 45 Colt lead bullets are .454,IIRC. A lot of old Peacemaker barrels were all over the place as far as throat dimensions, so there is a lot of variance in available .45 caliber bullets.

Mike Kerr
December 11, 2003, 10:23 AM

I think the . 451's are probably for 45ACP since they maxed at 230 grains. Seems most likely that the .452's are for 45LC since their weights are heavier. However, jacketed or lead can make a difference in a nominal .451 being .452 etc.

December 11, 2003, 11:08 AM
When I place a recent order for bullets the guy at the other end of the phone made a point of telling me that the bullets I was ordering were .451. I was ordering .45 ACP bullets. I asked what other options there were and he said that the .452 bullets were for rimless cartridges (revovers). So whenever I see the two different types, I use that bit of information to tell the difference between the two. Don't know if he was right or not, but I got the .45 ACP bullets I wanted and they have worked great in my loads.

December 11, 2003, 04:26 PM
Interesting. Rather than re-type and post the pictures, check out my thread over on Glocktalk: here ( Scroll down a-ways for the pictures.

December 12, 2003, 05:14 AM
The .451" is 45 ACP; the .452" is 45 LC; IME one may use bullets sized from .003" under actual bore up to .003" over.

As for actual pressure, some (others) testing suggests that it does NOT necessarily increase due to a larger-diameter bullet.

In my 1911 I've gone with .450" up to .453". I found certain bullets exhibited better accuracy at .451" than (the more 'conventional') .452".

As always, testing required in YOUR gun.........

(In some of my 357 loads I've gone from .355" up to .359". The bigger bullets seemed more accurate, except for one type that worked well sized .356". All very interesting............)


December 12, 2003, 10:06 AM
An interesting thread, but with all the talk about what is the proper size bullet don't forget that barrels vary also.

Nero Steptoe
December 12, 2003, 04:26 PM
I've used both .451" and .452" 230gr. jacketed bullets for loading for 1911's and Glocks, with absolutely no problems. If a bullet comes with a cannelure, that's a pretty good clue that it's intended for use in a revolver.

December 12, 2003, 10:05 PM
I use the same .451 sizer for both my .45 ACP cast bullets and my .45 Colt cast bullets. No problems noted.

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