Numrich H&A Underhammer 45

[planetmobius]

Recently I came across a Numrich Hopkins & Allen underhammer "Offhander" in 45 caliber. Having trouble finding information on it. Anyone know the rate of twist. I was wondering if it will handle conicals or if I'm limited to RB. Anyone know what kind of a charge it will handle? I'd like to field it as a hunting implement but I need to know more about its limitations.

 

[Prairie Dawg]

Round ball twist.
I've been told 1-in-56 and 1-in-66.
Either way, it's too slow to stabilize conicals.
I had one years ago that took a .433 patched round ball.
I have one now that takes a .440 patched round ball.
Depends on the thickness of the patch too.
I've known target shooters who shoot 35 grains FFFg.
I shoot 45 grains FFFg in mine
I've known hunters who use 65 grains FFFg

Loads & features for alot of these older guns are in Sam Fadala's BP Loading Manual.
Your local library might have a copy.
Useful book

Hope this helps
---Dawg

 

[StrawHat]

...or if I'm limited to RB...

You say that like it is a bad thing! The PRB has accounted for more game than probably any other projectile. Granted, the 45 is a small caliber but it is still big enough for deer.

 

[planetmobius]

Dawg, got the book, found the reference Thanks.

Straw Hat, not bad, just different characteristics.