doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Repair of Hammer Screw

I have a double rifle that has a screw on the right lock that holds the hammer on that will not tighten down. The screw is highly engraved, so I would like to save it. The threads on the screw look OK. What is the proper way to fix this, or who should I send the lock to to have it repaired?

New threads might have to be tapped and a new pin made. No worries about the engraving, it can be replicated on the new pin exactly like your original. I've Pm'd you on who to send it to.

It, whatever it turns out to be, was, more or less, handmade once. There are very, very fine craftpersons alive and practicing today. They can remake it. However, it sounds like the tumbler shaft's internal threads have been stripped; overtorqued enough during tightening to shear the thread bases (tumbler was softer than the screw). It might be possible to have the lock stripped and the shaft welded solid, redrilled, retapped, and re-heat treated. However, there may be issues with matching the screw's thread; likely will take a custom tap. Lot of speculation. Contact one of the "good guy gunmakers. IMO.

DDA

Just tap it out to a larger size and have a new pin made .Sorry Rocketman but your idea would be last resort as it makes a relativly simple job complex and costly . The original screw thread would hve been around a 5BA which had an OD of .126" 4BA at .141"is what I would tap out to or its metric equivolent [3.5mm] .

Or,you can make a casting of the hole with cerrosafe,unscrew it,and you can then measure the dia and pitch.Then you can decide what is required.
Mike

gunman, I'm sure you are right and no "sorry" needed; I duely recognize your experience with such problems. I was simply floating some ideas of how the problen might be approached. You would have to make a new screw/pin?

DDA

Hi LDI

This is a normal engineering problem and a not so difficult to solve, what you require is a helicoil fitted into what is left of the threaded portion I must have used countless thousands in my working life. Helecoils are not the sort of product that gunsmiths would normally come across or be expected to use but they are a bread and butter repair in light engineering. Check out www. Helecoil.com for information in how the repair works also they are not the only manufacturer of thread repair coil inserts. If you have a repair done with a helicoil type system you will still be able to use your original screw and the repair will be as good as new or even better.

The OP needs to state if the threads are stripped off the shaft. If it just loosens up after use a drop of blue Locktite is the answer after everything is cleaned up of oil and grease..

OK Mike tell every one the secrets of gunsmithing .

Put Acragls in the hole in the square shaft, coat the screw with release agent, screw it in, wait for the Acraglas to harden and back the screw out. Works for me, anyway, I've done that, degrease the hole first, of course.