Hopkins & Allen Underhammer Boot Pistol

[garypl]

Just bought an H&A Underhammer handgun/boot pistol and wanted to remove hammer and trigger to give it a good cleaning and lubrication. There are two screws/pins that hold hammer and trigger in place. I tried to unscrew both and the screws just rotate continuously but never come out. I tried pushing on the far side of the screw while unscrewing them and nothing changes. Tried to gently push them out and they do not budge.

Has anyone ever run into this type of problem? Everything seems to function just fine but I always like to give new guns a good cleaning and lubricate them. I think this gun has not been touched for 30-40 years. Bore is perfect and outside is good other than a little surface rust.

Appreciate any advice from anyone that has one of these.

 

[rusticbob]

A picture might be helpful

 

[hawkeye2]

They are screws and from your description they are stripped and the frame may be as well. Contact the seller and tell him about the issue, it should have been disclosed.

 

[Mousegunguy]

Does the head on the opposite side of the screw rotate to?

 

[garypl]

Does the head on the opposite side of the screw rotate to?

Yes

I bought from a friend out of state and only paid $100 and it appears to be in perfect shooting condition so I will first take it out and shoot it and if it works well I’m not going to worry about removing the screws.

 

[Mousegunguy]

Then to my mind it means the screw is seized up in the thru bolt, not stripped.
If you can prevent the rivet head from rotating you should be able to unscrew it.
Mine I just put finger pressure on the rivet head to prevent rotation and unscrew em for cleaning.

 

[hawkeye2]

Then to my mind it means the screw is seized up in the thru bolt, not stripped.
If you can prevent the rivet head from rotating you should be able to unscrew it.
Mine I just put finger pressure on the rivet head to prevent rotation and unscrew em for cleaning.

Yours must have a 2 piece trigger or hammer pivot pin. The only ones I've seen are one piece with the screw threads just under the screw head on the right side. The part showing on the left is the end of the pin (no threads this end) which is a close fit in the left side of the frame.

 

[Mousegunguy]

All mine are like this…..

 

[garypl]

View attachment 332352All mine are like this…..

Thanks for posting the pictures / first time I have seen an example. I expect mine is probably this type- I will try to figure out how to hold the female side to allow me to unscrew them.

 

[garypl]

Well, I was able to remove the hammer pin by clamping the barrel against my bench block (an old hockey puck) with a piece of duck tape against the pin on the bottom. Finally unscrewed the screw and there was a bit of rust in the threads.

Been fighting the trigger pin for an hour but it must really be rusted in place because nothing is holding the bottom of the pin from turning. I am soaking in Kroil overnight and will try again tomorrow. Next step will be drill a hole in the bottom of the pin and try an easy out on one side and a screwdriver on the opposite side. Going to check if I can get new pins from Numrich before I start drilling holes.

 

[No Answers]

So glad that you got it figured out. I own the identical pistol and was preparing to take a photo of those parts but I won't bother to now. Mine parts look like the ones that Mousegunguy already posted, but I was going to show clearly a flat blade screwdriver slot in each piece. Turning only one side will only spin the assembly around. You have to use a screwdriver on both ends at the same time.

For $100 I'd say you got your H&A for a low investment.

 

[garypl]

So glad that you got it figured out. I own the identical pistol and was preparing to take a photo of those parts but I won't bother to now. Mine parts look like the ones that Mousegunguy already posted, but I was going to show clearly a flat blade screwdriver slot in each piece. Turning only one side will only spin the assembly around. You have to use a screwdriver on both ends at the same time.

For $100 I'd say you got your H&A for a low investment.

My pins only have a slotted screw on one end - the other end is smooth and nothing there to grip except maybe filing a slot or drilling a hole for an easy out. I just checked Numrich arms and they do have new style replacement pins, which is what I believe I have, so tomorrow I will try again to remove the stubborn screw!

 

[2 shots]

maybe you can push the trigger to the side to put some pressure on the pin to hold it from spinning??

 

[garypl]

maybe you can push the trigger to the side to put some pressure on the pin to hold it from spinning??

Good idea - there is some side play in the trigger - I’ll give this a try in the morning!

 

[Mousegunguy]

So glad that you got it figured out. I own the identical pistol and was preparing to take a photo of those parts but I won't bother to now. Mine parts look like the ones that Mousegunguy already posted, but I was going to show clearly a flat blade screwdriver slot in each piece. Turning only one side will only spin the assembly around. You have to use a screwdriver on both ends at the same time.

For $100 I'd say you got your H&A for a low investment.

All of mine are only slotted for a screwdriver on one side and not.
The other end is rounded like a river head.
The screws don’t need to be super tight I dot oil on em before I put em back together

 

[Colonial Boy]

Before you drill for an easy out, try drilling two small holes in line and then file a screwdriver to form two pins to fit the holes. An old method used by some gunmakers of yore on their products to stop damage from the normal slot system.

 

[garypl]

All of mine are only slotted for a screwdriver on one side and not.
The other end is rounded like a river head.
The screws don’t need to be super tight I dot oil on em before I put em back together

Mine are the same type- I am going to put a little grease on the threads when I put them back in the receiver.

 

[garypl]

Before you drill for an easy out, try drilling two small holes in line and then file a screwdriver to form two pins to fit the holes. An old method used by some gunmakers of yore on their products to stop damage from the normal slot system.

Another good idea! I have a 2-pin bit in my screwdriver set that is narrow enough to fit on the end of the pin. I’ll post results depending on what works. Hope that a good soak in Kroil overnight will free up the screw without having to resort to more complicated methods!

 

[45man]

I don't knw if you can drill the pin. Being a pivot it might be super hard.

 

[garypl]

I don't knw if you can drill the pin. Being a pivot it might be super hard.

Good point - this would be a last resort for me. Hope by soaking in Kroil the stubborn screw will come loose! At least I see that Numrich has replacement pins if I damage this pin.