45 70 modern single shot loads

[Road_Clam]

Originally Posted by Barman54

First Post, Long Time reader.
HighPower Shooter for over 25 Years, and reloader longer than that.
I have a Pedretti Sharps, 45/70 trying to stabilize a 530 Postell using AA5744.
21.0 yields 1048, 23.0/1124, 23.5/1145, 24.0/1156 FPS.
Shooting at 100 yds I see a start of some keyholing, on some shots??

So you think bumping it a little might stabilize it??

Do not really want to get into BP, for now, I have good things about using it.

Had two Trapdoors (HR Replicas) to get the Pedretti, had good luck reloading for them, I learned a lot, about this Caliber.
Even loaded some for my Friends Marlin 45/70's, shoots cloverleafs out of them.

Just wanted to try a Heavier Boolit, than the 405 Hard Cast out of this Rifle.

Any suggestions would be helpful??

Barman54
Out

Few things come to mind, if you are observing random keyholeing that's usually lack of velocity as matched to your barrel twist. The other possibility is an undersized bullet. With my Pedersoli Sharps I run a .458 or .459 diameter (many shooters even have excellent claimed accuracy with a .460 diam bullet). The Pedersoli 45-70 chambers are specifically throated to chamber the heavy 500+ gr match bullets such as the Postell or the Creedmoore. I think Unclenick is offering good advice , I too think you need to up your load just a bit and get up around 1200 fps and see if you can stabilize your bullets.

[Barman54]

Unclenick, and Jasonzee,
Thanks for your Input.
Jasonee, Have real good luck w/405 and Unique, and a Host of other Powders, as the HR Trapdoors, just say you did not want to push them that much.
They shoot good in My Sharps Replica.
Unclenick, I can measure the Length of the Bullet, it is 1.400 in Length.
I cannot find the "Exact" Twist to this Rifle, it is in the Upper Teens??
THx,
Barman54
Out

[44 AMP]

I cannot find the "Exact" Twist to this Rifle, it is in the Upper Teens??

To find the exact twist of any rifle all you need is a cleaning rod, patches, a sharpie marker and a tape measure.

You can do it from either end, muzzle end is easiest, usually.

Put patches on the rod, so they fill the bore enough that the rod turns with the rifling. Put a mark on the handle end of the rod so you can tell one complete revolution. Start the patched rod in the bore until you feel it begin to turn. Put a mark on the rod at the muzzle. Push the rod in until one full turn and then put another mark on the rod at the muzzle.

Take the rod out and measure between the marks with the tape measure. That will show you 1 turn in X inches. Tougher to describe than to do.

Good Luck!