[swifty]

A friend has several French revolvers marked 1873 St.Entienne..they were orginally a 11 mm.With a very small amount of boreing, He has bored them out to 45 cal.He has slugged the barrel to confirm the cal.
Problem is they were orginally black powder. What smokless
powder will approximate the pressures of a 45 cal 45 cal.
What powder to use and source of supply?

 

[Bartmasterson3]

I'm not sure if AA XMP-5744 works in pistols but in rifles it can be loaded close to BP pressures and it's bulky. As for suggested loads...I have no idea. You might jump over to www.sixgunner.com and ask the question there. Some of those guys have lots of experience doing things most people wouldn't attempt.

 

[Gunnut45/454]

swifty
You should not use smokeless powder in those guns!!!! It's accident waiting to happen. Smokeless powders pressure spike with greater energy than those pistols can probably handle. Your going to be playing with a bomb and you will not know when it will blow up. Don't do it.

 

[birddogman]

Amen

Heed the Gunnut. Some things are just not meant to be done.

 

[imashooter2]

I concur, smokeless in a black powder piece is bad juju. Why not try one of the non corrosive black powder substitutes? No rust and you get to keep all your digits.

 

[retiredspook]

All of the new made black powder revolvers say"Black Powder Only" and they are made with modern steel. Heed the above comments mightily.

 

[ribbonstone2]

A friend has several French revolvers marked 1873 St.Entienne..they were orginally a 11 mm.With a very small amount of boreing, He has bored them out to 45 cal.He has slugged the barrel to confirm the cal.
Problem is they were orginally black powder. What smokless
powder will approximate the pressures of a 45 cal 45 cal.
What powder to use and source of supply?

Been some work done on black powder vs. smokless powder in the way they develop pressure...even at the same peak pressure, there seems to be a difference.

Not saying other people haven't used smokeless in thse old big bore revolvers and gotten away with it, but it just seems a waste to have done some much work and then subject it to loads/powders it was not designed for.