Underhammer Suggestion

[Lostinidaho]

I have shot several of my friends muzzle loaders and have enjoyed the experience. So I wanted to build my own. I have a thing for firearms that you can change the barrels on (multiple calibers/rifled or shotgun etc). I like to build box cases that hold the firearm, extra barrels etc.

I have decided to build an H&A Underhammer from Petaconica River Long Riffle Supply. I have even saved up the money.

http://www.longrifles-pr.com/underhammer.shtml

But I cant decide on which barrel to begin with. A .36 for a cheaper to shoot target small game rifle. A .45 with a fast twist for long range. A large bore barrel, its awful fun to shoot a large bullet down range. Or a shotgun barrel.

Mostly it is for target shooting. I do go upland bird or turkey hunts.

What are your thoughts and reasons.

[1Hawkeye]

If Pecatonica copied the way Deer Creek Products was attaching the barrels to the frame you could do one rifle with several barrels. Deer Creek used set screws at 9, 12, & 3 o'clock positions in the frame to hold in the barrel. I built a .50 cal bench gun using my .36's frame and stock but put a Green Mountain 1 1/8" x 42" barrel. Later on I got the parts and built a complete rifle for the spare barrel. I think if I was going to build another one it would be a .40 cal.

[Edward]

I went with slow twist 45 cause it doesn"t hurt ,less you are looking to add weight for shooting long the under hammer in 45 is a great squirrel gun . Fast twist for me means a heavy barrel (weight) and I already own a sharps and maybe I just don"t weigh enough (135 )

[kens]

I saw those actions and was thinking about the same thing. you could have a squirrel rifle, deer rifle, long range rifle, shotgun,,, you name it.
I would like to have a rifled slug 20ga barrel

[charlie b]

I thought the action had the breech plug integral to it and the barrel threaded to fit.

I guess you could use anti-seize and have different barrels fitted and just unscrew to change?

I've been looking at the Allen underhammer action from Pecatonnia.

[dondiego]

I thought the action had the breech plug integral to it and the barrel threaded to fit.

I guess you could use anti-seize and have different barrels fitted and just unscrew to change?

I've been looking at the Allen underhammer action from Pecatonnia.

The barrel contains the breech plug and that action can be used with many barrel types. I built one of the Pecatonica's in 50 cal slow twist, but many of my other barrels will fit this action/receiver, even the original H&A barrels which had the pin running through the breech plug.

[charlie b]

So, the breech plug acts kinda like a hooked breech? Different barrels can be put in place?

[1Hawkeye]

Yes, the barrel is held in place by 3 set screws that press on the back of the breech plug. Its a little more complicated than a hooked breech plug but you can still swap barrels you just need an allen wrench for the screws.

[oldracer]

When I built up my under hammer I used a Green Mountain 1 in 18 45 caliber barrel. I shoot 540 grain grease groove bullets and so far have had excellent grouping out to 200 yards. I figure it can shoot much, much further but our range only goes to 300. I used the Allen action as it is adjustable and I have about a 2# trigger pull. With my 58 caliber H&A based rifle the pull is about 5# or so and can't be changed. Pecatonica River does a FANTASTIC job getting things ready for you to do the build.

[Hanshi]

I have an H&A underhammer I ordered over 50 years ago. Extremely accurate gain twist barrel in .45. It would interchange barrels, I'm sure, since the breech plug was in the barrel and a large friction fit bolt held it on the frame. I never tried switching barrels but killed deer, bobcats and squirrels with this good gun. The spring that powered the trigger & hammer was also the trigger guard. That spring died on me years ago.

I do know for sure about those old guns but I don't see why not.

[charlie b]

The Allen action looked interesting too, but, it does not seem to accommodate interchangeable barrels.

[rhbrink]

I just happen to have a Green River 1 inch with a 18 inch twist set up for a switch barrel for one of the Pecatonica actions this has a breech made and installed by David McCandless and shoots very well I just don't shoot it much any more and would be happy to sell it $250 shipped to anywhere in the lower 48.

RB

[oldracer]

As I noted above, when I got my parts and such from Pecatonica River and talked with them for a bit on the telephone. I was told that the barrel screws into the Allen action which I used since it is adjustable for pull. I am not sure what the torque values is for tightening the barrel but I imagine it is about the same as most other breech plugs? You can give them a call as I have done that several times and they seem to take the time and not rush you.

When I ordered mine I asked them to cut all the necessary dovetails I.E. front globe sight, forearm mount and such. The only problem was when I flat filed the barrel before bluing I had to be super careful not to get into the sides or top of the action.