45acp from a 45 Long Colt Rifle (Sharps)

[singlestack45]

Lots of people convert their 45 Long Colt revolvers to also fire 45acp from moon clips.

Has anyone done this conversion with a rifle? Seems like it should be particularly easy with something like the Sharp's, as it is single shot. You ought to be able to use a modified single shot "moon clip" and shoot either 45acp or 45LC.

I'm itching for something like a Sharp's, but want to be able to use calibers I already have.

 

[singlestack45]

...or convert from 45-70 to 45acp?

 

[singlestack45]

ballistics

...and yes, I realize there's a huge ballistic difference. But I'd love to practice with ACP at 50 yards and then haul out a 45-70 occasionally for longer shooting. I realize the rifle is/was intended for long range shooting.

 

[rcmodel]

I don't think it would work due to headspace differences.

Rim thickness on .45 Colt is .060".
It is .065" on 45-70.

Rim thickness on .45 Auto-Rim is .089".
And that would be the same with .45 ACP held in a C-clip moon clip that would even fit in the 45-70 or .45 Colt chamber .
So, the additional .024" thickness with .45 ACP would prevent the action from closing.
.45 Colt would set .005" too deep and might give ignition problems.

The other problem with 45-70 is a tapered case, .504" in dia right in front of the rim.
The .45 ACP is only .476".
.45 Colt is .480.

So the 45-70 rifle chamber would be .028" bigger then the .45 ACP case.
And .024" bigger using .45 Colt.

The logical solution to your practice ammo is to down load the 45-70 case using igniter cast bullets with a light powder charge.

They get around it on revolver moon clip conversions by leaving part of the rimmed case chamber in place where to openings in the moon clip can miss then and insert fully into the cylinder.

That is not an option on a single-shot rifle.

rc

 

[Jim Watson]

And a .451" bullet would not hit much out of a .458" barrel, either.

 

[Malamute]

And a .451" bullet would not hit much out of a .458" barrel, either

A Ruger No 3 in 45-70 cal I had years ago, a 230 gr 45 auto bullet would just barely drop through the barrel, with one slightly snug spot, but it could be easily pushed through the snug spot with a rod then drop out the rest of the way. Not a recipe for accuracy.

 

[Goody3086]

I know several people who use 11 to 12 grains of unique, any lead bullet, for a nice light load on the 45/70. Bonus here is that you don't foul up your chamber. They say they get a little over 1000 fps with 300gr bullets.

 

[Malamute]

140 gr collar button bullets or round balls are also nice for light loads in 45-70. I dont recall thew numbvers, but both are at their best when run pretty lightly I believe. I think I'd drop back to about 6 1/2 grs and mayb e run up to 9-ish. Some of the older manuals (like the old Ideals) had such loads listed.

I use those type loads for grouse in the 45-70. Its not very loud and doesnt tear up the birds much.

 

[highlander 5]

I have a Saeco mold that casts a 250 gr wad cutter that I use in my 2 45/70s for a gallery load.
With linotype or No 2 alloy it casts at .456 or so and out to 50 yds is decently accurate. Saeco makes a 225 gr wadcutter block but I believe the 250gr is a "custom" block that is made on order.