Black powder pressure

[bigdog454]

Could anyone give me a good estimate of the chamber pressure of a black powder 50 cal muzzle loader using a sabot and 300 gr bullet?

[405]

A little more info would help and the foolish like to estimate pressures.. Like how much powder and type of powder, etc., etc.? I know that the BP black rifle crowd likes to shoot all the P pellets they can to impress someone :roll: I wouldn't hazard a guess about pressure from some of the loads that folks try in those things including some of the smokeless types.

The Lyman data is:

300 gr in Hrndy Sabot with Pyro RS by vol 40gr at 5,700 PSI

300 gr in Hrndy Sabot with Pyro RS by vol 120 gr at 15,400 PSI

300 gr in Hrndy Sabot with Goex FFg 40 gr at 3,400 PSI

300 gr in Hrndy Sabot with Goex FFg 120 gr at 12,200 PSI

[bigdog454]

Well I was thinking about relining a 12 ga double bbl shotgun to a 50 cal ML barrel. the Shotgun chambers measure ~.800 with the muzzle at ~.700, and I was wondering if there was enough metal left AND would it be strong enough to take the pressure of up to 150 gr of black.
OR: will I have to cut the barrels use the block and build from there?
BD

[missionary5155]

Good morning
I have shot my double Fox B 12 with 135 grains 2F and .685 RB many times. Recoil is plain awful. But with a relign job I would think there would not be any pressure problems as your projectile is only 75% of a .685 RB.
My question would be if this is a modern reciever.. Breach thrust will be a concern. The Fox B receivers are heavy and easily contain modern 2 3/4 slugs.
Mike in Peru