Can I load .451 caliber jacketed bullets into 45 Long Colt cases?


October 22, 2011, 12:20 PM
I have a bunch of unused .451 caliber jacketed bullets intended for 45 ACP. Can I load these into 45 Long Colt cases for firing out of a revolver?

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October 22, 2011, 12:24 PM

You may have to turn down your expander button to get enough case neck tension though.

A light crimp into the jacket is all you can do as there will be no place to roll-crimp on an auto-pistol bullet.
So good case neck tension will be necessary to prevent bullts pulling from recoil.


October 22, 2011, 01:11 PM

I use a powder thru expander die to bell the cases. Do you mean just dont bell so much?

October 22, 2011, 01:16 PM

I mean if your expander / belling die is made for .452"-.454" .45 Colt bullets, .451" .45 ACP bullets will be looser in the case.
Probably too loose.

The expander part that goes down inside the case before the bell function comes into play is the part I am talking about.


October 22, 2011, 02:04 PM
Your saying turn down as in turn the part & take the metal down?

October 22, 2011, 02:23 PM
That is what he is saying.

bullets are held in place mainly by case (or neck) tension.

The inside diameter of the case is smaller than the bullets outside diameter.

It is an interference fit and the brass stretches as the bullet is seated.

The elasticity of the brass creates the tension to hold the bullet in place.
If you want to load a smaller than normal bullet you will need to make sure the brass is not expanded larger than required or the bullet tension will be lowered (or even zero and the bullet can fall back into the case.

This will cause problems when you want to use normal size bullets.
The brass will be worked excessively and harden faster than otherwise, and may even simply split with a larger bullet seated.

You might try trading/selling the bullets to someone who can use the and avoid the whole problem

Depending on the loading and barrel diameter, you may have bullets that cannot seal the bore or engrave on the rifling.

Accuracy will be very poor.

Dies cost a lot more than bullets.

October 22, 2011, 02:41 PM
Ruger makes a New Model Blackhawk with interchangeable cylinders in .45 Colt and .45 acp. As stated above all you need is a smaller expander button or if your lucky a set of .45 acp dies.

October 22, 2011, 02:56 PM
I use a .45 ACP carbide sizer die to size .45 Colt cases. Sometimes I use 200-grain SWC bullets designed for the .45 ACP. When I do, I use the .45 ACP expander button in the .45 Colt die to expand to the correct diameter and to the proper depth. I lightly roll crimp over the front shoulder of the bullet. No problems and accuracy is good.

I've also used a 230-grain RN lead bullet with a tiny shoulder...RCBS mould...and again roll-crimped over the shoulder. With 8.5 grains of Unique, it makes for a nice, accurate plate rack load that knocks'em down with authority. With these, I also use a modified SWC top punch for the bullet sizing operation. It flattens the nose a little and makes 'em look like the original 250-grain RNFP bullets. Kinda goes with the New Vaqueros. People ask me all the time where I ran up on that mould. :cool:

October 22, 2011, 09:37 PM
I've shot a few acp bullets in my 45 colt guns.

Here's a bit of info on what I've been doing. (




October 23, 2011, 12:28 PM
I did not notice any funnies. As long as you have good case neck grip they will shoot just fine.

5 1/2" USFA Rodeo

255 LSWC (.454") 8.5 grs Unique thrown, R-P cases, WLP primers
12-May-02 T = 84F

Ave Vel = 844
Std Dev = 33
ES = 117.8
High = 907.6
Low = 789.8
Number Shots 12

240 JHP Sierra (.4515") 8.5 grs Unique thrown, R-P cases, CCI300 primers
12-May-02 T = 84F

Ave Vel = 848
Std Dev = 54
ES = 146.4
High = 911.8
Low = 765.3
Number Shots 6

Shot these in a 5.5 " Colt New Service

230 FMJ 9.0 grs Unique R-P cases WLP (nickle)
24-Sep-99 T = 78 F

Ave Vel = 839
Std Dev = 86
ES = 360.9
High = 931.9
Low = 571
N = 12

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