[ShawnAgne]

From what I've read Pyrodex RS is the same as FFg Blackpowder. Now my question is this, can I use 70 grains of Pyrodex RS instead of FFg blackpowder as it calls for in Spencer Wolfs book? Or will this result in the preasure being to high? Thanks in advance.

Shawn Agne

 

[Pooter/Shooter]

I've shot both and pyrodex did a couple nof things, you don't need quite as much as you would ffg and I found it to be more gunky during clean up. I know they say that it's cleaner but for me it wasn't that way. After all was said and done I switched over to fffg and got far better results in my shooting and cleaning. I have a 54 thompson and strickly shoot 80 grs of fffg.
Bob

 

[ribbonstone]

Guess you know this, but don't load loose Pyrodex by weight...load it by volume. If you use the same volume of Pyrodex as 70gr. of FFg, you'll get a bit more velocity but the pressure will be close to the same.
Assuming you have a modern repro. rifle in good contion of .45cal or larger, the 70gr. load (either powder) should be well within pressure limits.

 

[ShawnAgne]

My rifle is an 1873 Springfield Trapdoor. So I guess my question should be worded do I use a 70grain volume of Pyrodex RS to substitute for 70grains of FFg.

 

[ribbonstone]

If it's safe with 70gr. of FFg, it will be safe with the same volume of pyrodex. Pressure-to-pressure it's a safe load.

Couple of things to consider. Old rifles often have over sized bores so it's worth slugging/measuring the bore...one 1883 dated Rolling Block has a .461" and my firend's trapdoor runs .460", but have other people's numbers that show anything from .457" to .463" isa possible. BP usually will usually "bump up" a soft alloy bullet well and shoot accurately; hard alloy bullets often just key-hole.

Other thing to know is that while Pyrodex cases will need a trhough soap-and-water cleaning and brushing...and even then, better to check them in a day or two to see if they are growing green fungus.
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Not enough data, but fo far tht only substitute powder that is giving consistantly much higher velocity than expected is Triple Seven. I don't believe there is a free lunch...higher velocity is going to have to equate to higher pressure. May not be high enough to damage an old gun (and trapdoors are evidently a lot stronger than their reputation), but I'll be conservative.