Newbie question, which bullet for .45 ACP .451 or .452?

I currently shoot factory .45 ACP but have ordered a progressive press for pistol rounds. I don't understand the significance between .451 and .452 bullets. I looked in the forum search function but didn't find an answer.  As a newbie, I would not think there would be much difference in performance of a .001 diameter. Given that both are manufactured by the same manufacturers, there must be a material difference that I am missing. 
My apologies if this is a repeat question asked many times before.

Thank you,
AGG

.451 for jacketed and .452 for lead.  At least that’s the consensus.  But you can generally use any bullet diameter between .450 to .454 with varying success.  The loads typically used in bullseye are mild enough any spike in pressures with big diameter bullets are minimal.

I'll add, there's some small chance loading larger than 'normal' bullets, like a 454 in an ACP ... 'MIGHT' result in the cartridge being a tighter fit in the chamber than desirable.

452 is sort of the 'standard' for lead. Also, use a proper expander ... hint ... 'Photoescape' ;-)

454 is in some way a 45 Long Colt thing ... but my single action had 457 throats ... weren't nothin' gonna fix that piece of junk.

A friend of mine that I shoot with gave me a load that has improved the accuracy of my S&W 25-2 using a 200gr SWC that is .454" diameter.

Bill

It depends on barrel. Most stuff works well with .451-.452. Just use good practice developing your load from the start and you should be fine.

messenger wrote:A friend of mine that I shoot with gave me a load that has improved the accuracy of my S&W 25-2 using a 200gr SWC that is .454" diameter.

Bill

Yes, the 25-2 cylinder throats were all over the place.
The .454 resolved many accuracy issues

Either if jacketed. For lead, you should slug the barrel and use a bullet at least 0.001" over measured groove diameter.
For 9x19 jacketed bullets, I load.355-.357" without issue.

I am not familiar with the term slug the barrel, can you please explain?
Thank you,
AGG

Take a pure lead ball just a bit bigger than your barrel groove diameter then drive it through the barrel. Then measure the lands on the slug as the grooves form the lands on the slug.   It’s not difficult but if you haven’t done one before it can be easy to cause damage to your gun.  Unless you’re dealing with a VERY old barrel I’d just assume that it’s .451 diameter.

Use a wooden rod or similar composition to drive the lead ball if you decide to do that.

I have two 1911's a Dan Wesson PM-7 and a Les Bare National Match both of course are .45ACP. purchased


I have four 1911's in 45 ACP. The most accurate are my Les Bare Nation Match and my Dan Wesson PM-7. It sounds like I should defer the barrel slugging to a more skilled hand.
Thank you for the explanation.
AGG

Or take a swaged bullet and lightly hammer it a little shorter and fatter to slug a barrel