Jacket vs Cast Velocities in a 45-70

[mkl]

I just finished loading a box (20) of 45-70 cartridges with 51.0 grains of IMR 4895 behind a 350 Oregon Trail Laser Cast bullet set off with CCI 400 primers.

This is at the "starting load" range for jacketed bullets for my Marlin 1895.

I can't seem to find any data for lead bullets in this weight, so I used the low end of the jacketed bullet data.

I'm guessing velocity around 1500 fps, but until I get a chance to chronograph in a few weeks, it is just a guess. Since the very hard cast Oregon Trail bullets say they will not lead at under 1800 fps or so, I think I am okay.

Anyone shot 45-70 lead and jacketed bullets around 350 grains with identical powder charges and observed if there are any significant velocity differences?

 

[rcmodel]

Lyman #49:
They don't even use any 4895 with lead bullets.

Hodgdon shows a 24" barrel, trap-door load:
385 grain lead with 44.2 starting load @ 1,412 FPS
Max is 47.0 @ 1,486 FPS.

Somehow, I always thought of IMR-4895 as being too slow for the 45-70.
Especially with light lead bullets.

rcmodel

 

[Rustler]

I'm using 27 grains of IMR-4759 out of a Sharps 28' barrel and I can thump easily out to 500 yards with a 405 GR Bear Creek (Molly) bullet. This is not a "light" load and thumps me after about a dozen or so shots...

I don't know anything about IMR-4895, but it sounds like 51 grains will be really "hot"... and the Marlin 1895 is not a heavy rifle!!

I also have a Marlin 1895, but am using 12.9 grains of Trail Boss and it seems to shoot well and not rip my shoulder off.

I don't use these loads for hunting - just Cowboy shooting.

 

[rcmodel]

Well 61.0 Compressed is a max Marlin load with a 350 Jacketed bullet.

I just somehow doubt it's going to work too well without the jacketed bullet bore friction to allow it to burn right.

I believe that is why no one recommends 4895 for lead bullets in the 45-70 mid-level loads.

They are slick like owl do-do compared to jacketed bullets.

rcmodel

 

[mkl]

Somehow, I always thought of IMR-4895 as being too slow for the 45-70.
Especially with light lead bullets.

It may well be. I had a full pound left over from who knows when that I don't use in any of my other reloads. It does give 100% loading density at 51.0 grains -- no compression, the 350 grain bullet exactly touches the top of the powder charge.

Hornady #4 gives 50.2 grains start, 58.3 grains max with a 350 grain jacketed bullet and H4895 in the Marlin 1895. Speer #11 starts at 50 grains and goes to 54 grains max with a 400 grain jacketed bullet.

I'm pretty sure the load is safe in the Marlin 1895 (24-inch barrel). I just did not want to exceed 1800 fps because of a possible leading issue. I also know this thing is going to seriously recoil when I pull the trigger.

I want to hunt deer next year with the 45-70 and a cast bullet. That's what the load is for. I shoot much milder loads for fun.

 

[huntershooter]

I just zero'd and did load work up for a Browning "86 Winchester yesterday.
I'm running H322 and a 420 gr. WFNGC. Barrel is 26".
The suggested "starting load" was 47 gr. That chrono'd 1800 fps (1796 avg.).
You would be correct regarding the "serious recoil" off the bench.
That load was good for 1.5" 3 shot groups @ 100 yds. with tang/aperture sights. Certainly "minute of Bison".

 

[mkl]

Thanks for the input. I'll chronograph five or so, and if the velocity is over 1700 or so or if they are super dirty, I'll just pull the rest.

I have printed out your replies and will tape them to the box of ammo.

I do appreciate the advice.

Many thanks.

mkl

 

[mkl]

Deleted.

 

[Jefferson Herb]

45-70

Rustler,what kind of velocity do you get w/28'[ft] barrel?In that length ,you might want to try 5010.I know, it's a typo,I use 28 gr 4759 w lyman 405.I also have a 413gr spitzer [sharps?] type that I've never seen in new molds.