.45 bullets

WWllVet

I remember that load data for bullet size was .452 for 1911A1, .454 for Colt, and ,458 for .45-70.
Now all I am seeing is .451 for 1911A1, .452 for colt.
Why the change?

goldeneagle76

.451 for jacketed and .452 for lead bullets is my understanding for 45acp loads.

richarda

.454 was for original .45 Colt - chambered guns BY Colt, pre WWII. At some later point, barrel dimensions were changed to take .451/.452 bullets like .45 ACP.

charliemeyer007

Likely just logistics to standardized 45 cal pistol bullets.

noylj

The important thing is to slug your barrel so you know what the right bullet is for your gun.
SAAMI spec for .45 Auto is a 0.4520 +0.000/-0.003" jacketed and 0.4530 +0.000/-0.003" bullets with a groove diameter of 0.450 +0.004/-0.000". Any one want to try a 0.450" lead bullet in their .45 Auto?
For .45 Colt, SAAMI calls for a 0.4560 +0.0000/-0.0060" bullet, jacketed or lead, with groove diameter of 0.450 +0.004/-0.000". Thus, a 0.454" .45 Colt bullet is still per SAAMI specs for all .45 Colts.
So, based on SAAMI alone, one should always slug their barrels.

DBMJR1

I just bought a brand new Ruger Blackhawk .45 caliber convertible.

First thing I did was slug the barrel. I was expecting .452 for the .45 Colt, but it's exactly .450.

Now I'll have to size my .454 Keith 255 gr Lyman bullets down to .452.

Good news is that .45 acp ought to be accurate out of it.

noylj

I would really try as-cast bullets before EVER considering sizing my cast bullets.
Start with the starting load and see how they do.
Don't forget, for your revolver, the cylinder's throats are also critical.
Bullets should be at least a snug slip-fit in the throats.

peddler

Most Colt saa's have thoughs that are over sized, mind is .457-.458".