.455 brass from .45 Colt

[PJ Hardtack]

Yesterday I picked up the .455 cases that a friend cut down from .45 Colt. I gave him a couple of Dominion .455 cases and he went to work. He even borrowed a case trimmer from another mutual friend and cut them to exact length. I think I'll be taking him and his wife to lunch today after church!

I just ran them thru' a .45 Colt carbide sizer die and they chamber beautifully in all my .455 revolvers. I have 100 such cases from a previous operation and at .455 pressures, I expect they will last as long as I need them.

For the record, he says he needed to reduce the rim thickness of the once-fired Starline brass by 14 thou. Don't bother using collectible Dominion brass or buying expensive Fiocchi brass primed with small pistol primers.

[Four Eyes Henry]

Is the 45 cowboy special not very close to the 455 (MK1)?

[PJ Hardtack]

Four Eyes

Maybe. Got the case specs on the .45 Cowboy Spl.? Compare it to the specs Grant posted on the topic of Brit .455 ammo. Regardless of case length, it will be the rim thickness that is the problem.

[Sir Charles deMouton-Black]

Four Eyes

Maybe. Got the case specs on the .45 Cowboy Spl.? Compare it to the specs Grant posted on the topic of Brit .455 ammo. Regardless of case length, it will be the rim thickness that is the problem.

.45 Special is a .45 ACP case with a .45 Colt rim.  It is an easier conversion to .455 as only the rim has to be thinned.  The marginal benefit, as a case, is that the .45 ACP inside taper makes it seal better than a shortened .45 Colt.

[Tascosa Joe]

Is there and easy way to thin the rim?  Will primers be protrude?

[Sir Charles deMouton-Black]

You must thin the rims from the front.

With a lot of time on your hands you can do it with a 3-corner file with one safe side.  Most machinists, even home-grown, can figure out a quicker solution.

[Virginia Gentleman]

Using a lathe is the fastest way to do it.  I wish there was a kit for hand tools to do it as I would make some of my own this way out of .45 Cowboy.