Numrich arms underhammer reassembly and problems

[TrippyMcGuire556]

So I got a numrich arms underhammer as part of a package deal at an auction. Unfortunately the trigger spring was not strong enough to hold the hammer back at full cock. I took the thing apart not knowing how much of a pain this was going to be to put back together. Pictured is the part I cannot figure out how to reinstall properly. The only guide I can find shows a completely different spring system. If anyone here can help. It would be much appreciated as I have spent longer than I care to admit failing to put it back. Also, what calibers were these made in, as my .50, .52, .54, and .58 round balls all roll freely up and down the barrel.

 

[hanshi]

My H&A Numrich underhammer (.45) is a very early one and relies on the TG/hammer spring to act as a trigger return. Yours is apparently a later model. When I bought mine it was only offered in .36 and .45. Photos of the gun would help identify the problem; post a few pics of the gun.

 

[M. De Land]

So I got a numrich arms underhammer as part of a package deal at an auction. Unfortunately the trigger spring was not strong enough to hold the hammer back at full cock. I took the thing apart not knowing how much of a pain this was going to be to put back together. Pictured is the part I cannot figure out how to reinstall properly. The only guide I can find shows a completely different spring system. If anyone here can help. It would be much appreciated as I have spent longer than I care to admit failing to put it back. Also, what calibers were these made in, as my .50, .52, .54, and .58 round balls all roll freely up and down the barrel.

Mine is difficult as well but is of the older style of one piece trigger and the the trigger guard is the main spring. I have to use a punch of similar diameter to get the trigger pin back in. The punch is introduced from the opposite side to keep the hole lined up while the pin is inserted from the other side. The pin pushes out the punch as the hole is kept in line.

 

[bubba.50]

No help with your trigger problem but, try wrappin' the 58cal roundball with a patch and see if it still 'rolls up & down' the bore. if it does it's likely a 20ga.

 

[TrippyMcGuire556]

I have to use a punch of similar diameter to get the trigger pin back in. The punch is introduced from the opposite side to keep the hole lined up while the pin is inserted from the other side. The pin pushes out the punch as the hole is kept in line.

Tried that with a screwdriver of similar diameter. No luck sadly.

Hansi, I will link a video when I get home from work to detail the problem.

 

[hawkeye2]

That's the 3rd. trigger spring setup I've seen for the H&A action. If you use the punch (as described above) inserted from the left to hold the trigger and the piece the spring rests on aligned while you install it as in your photo you shouldn't have any trouble. It really doesn't take much trigger spring pressure to hold the nose of the sear in the notch on the hammer and you can test this be gently pushing forward on the trigger as you cock the gun. If it won't stay engaged check the sear nose on the trigger for damage (often caused by striking the half cock notch). Check for a worn full cock notch in the hammer too. It shouldn't be difficult to find a longer or stronger coil compression spring for the trigger if that's what's needed, possibly someone modified that one to lighten the pull.

.58 was the largest rifled caliber H&A manufactured so someone could have rebarreled it or it's a shotgun.

 

[TrippyMcGuire556]

Here's a link to the vid of what's happening. The hammer will not stay back at full cock. Also included is a pic of the hammer. If it looks like there is damage, let me know.

 

[jdw276]

To me the notch is ot cut deep enough?

 

[bubba.50]

The angle of the full-cock notch on the hammer looks off to me.

 

[TrippyMcGuire556]

Looks the same as my pistol that works fine so I dunno.

 

[hawkeye2]

The full cock notch in the hammer has been damaged by bubba possibly the trigger too.. Take the hammer out of your pistol and try it, they interchange. Did you try pushing forward on the trigger while cocking the rifle?

 

[TrippyMcGuire556]

The full cock notch in the hammer has been damaged by bubba possibly the trigger too.. Take the hammer out of your pistol and try it, they interchange. Did you try pushing forward on the trigger while cocking the rifle?

If I hold it forward, it holds in place till I stop. I'll try swapping the trigger to see what happens. Might just try and find a replacement spring too.

 

[toot]

very odd??

 

[bubba.50]

If I hold it forward, it holds in place till I stop. I'll try swapping the trigger to see what happens. Might just try and find a replacement spring too.

that makes me even more believe the full-cock notch and/or the hammer notch angle is off.

 

[M. De Land]

that makes me even more believe the full-cock notch and/or the hammer notch angle is off.

I agree, I just had to re-stone the angle on mine to get the let off the way I wanted.

 

[TrippyMcGuire556]

To everyone saying the full cock notch was damaged, that was it. Squared it off with a dremel and now it holds no problem. Shot it a bit today too. Puts holes through paper well enough.

 

[hawkeye2]

Glad you fixed it and without having to replace parts.

 

[hanshi]

They are excellent shooters!