Underhammer hangfire problem

[jimbo15563]

Okie,

Here is a link to Powder Inc.

http://www.powderinc.com/

They ship as little as 5 lbs, and you can mix types.

You might want to forget about the Pyrodex and shoot the real stuff-it's much easier to ignite. I'd try Goex FF (instead of Pyrodex RS) or Goex FFF (instead of Pyrodex P). The FFF would ignite the quickest, but your loads need to be 15% or so less than FF.

Also, here is a link to Blue Grouse

www.underhammers.com/

If you email Bruce, he might be able to sell you a better nipple or suggest another fix.

I'm fascinated by the underhammers and am considering having one built. I'd be very interested in hearing about your underhammer experiences:

Jimbo

 

[WV_Hillbilly]

It sounds like everybody that has commented, has hit on one or more of the variables that might be causing your problem. One thing about the H&A Uunderhammer style gun--they have VERY quick ignition properties. That short throw hammer arc and the straight path to the propellant makes for a really fast "lock time". I love the Underhammer guns...

It sounds like it could be a combination of a couple things. Pryodex definitely needs good compression for normal ignition characteristics. Prodex can sometimes burn more like a "fuse", instead of how it should ignite--quickly and more explosively.

Take the nipple out, if you are getting light through the nipple, it should work fine. I check the flash hole in the nipple with a size 7 sewing needle, which should slide easily through--works as a pick as well.

You should diligently seek some FFFg Black Powder to try if possible... perhaps a shooter friend, or another forum member nearby could give you enough to try...?

The information that came with my.45 Underhammer shows 80gr of FFg as maximum load. The finer FFFg should work also, but I wouldn't go over 65-70gr as maximum.

75gr of Pyrodex RS is roughly a maximum load. Just make sure that you used a Black Powder volume measure set at 75gr, and did NOT weigh the Pyrodex charge on a scale. If that Pyrodex RS charge was "weighed" at 75gr, it would be the equivalent of about 107gr of Black Powder FFg--that would be considerably OVERLOADED!!!

Yes, you can contaminate the propellant by using too much grease, or a grease with low viscosity. The combination of a "runny grease" and "not enough compression", would be a very real possibility of causing a "hangfire" symptom.

If you take the variables out of the equation logically, you should be able to determine the actual cause of all your grief. Those are good guns and you should have a lot of enjoyment from it.

Shoot Safely,
WV_Hillbilly

 

[CoyoteJoe]

Numrich Arms barrels in .36 or .45 caliber always run a bit tight, more like .35 & .44 caliber. If you try to compensate with a very thin patch it probably won't be sturdy enough to shoot accuratly. Try .433" ball and thick patch.
I'm inclined to think there is something going on here that we all are missing. Got to be something more than just Pyrodex, it works in other guns.
Got to be more than just a small nipple hole, they're all small (granted some more than others) but in an underhammer it should fire, and it does fire, just hangs a bit.
I once dry balled an underhammer and it would still fire the charge loaded on top of the patched ball which I had rammed down to the breech. The nipple seemed to be about 1/4" ahead of the breech face which let the cap blast just sneek past the ball rammed tight to the plug. :hmm: :hmm:
PS, I believe the 1/4X32 nipples from Track O' Wolf will fit the Numrich.