"Simple" fix... Did I do good or evil?

[Ed Ames]

Question for the gunsmithing court...

I recently picked up a little break action rimfire long gun. The action felt solid when I got it but as I was checking it over a third time I realized the action wasn't really locking closed - a sharp whack would pop it open.

I looked it over and after disassembly realized that the latch bolt wasn't engaging with the notch in the barrel lug. Everything else about how the action closed seemed correct, so I went to work with a file, some dychem (to mark the contact points), and a whole bunch of try fitting... I opened the lug notch enough that the bolt could engage.

Then I reassembled everything and found that the trigger guard/cocking lever/barrel release would not unlatch the barrel (I don't think it ever worked). I found a spot where the cast steel guard was supposed to cam the latch back but had obviously been filed down too far for the newly increased travel of the latch bolt.

The trigger guard is a rough casting with what looks to me like bad fake color case hardening. I tested by smoothing out some mold flashing with a file and it isn't hard.

I removed the trigger guard and used a TIG welder to add a very small amount of steel to the cam surfaces. I then filed it down smooth.

The gun now latches securely, opens correctly, and seems good to go. But...is that the right way to go about such a repair? Did I cause myself trouble down the road?

Obviously I think it is OK or I wouldn't have done it, but I'm interested in second opinions.

Thanks,

 

[john323]

break top

I think it should work fine. You are shooting 22 rimfire....give it the" pull string test" to be sure and have fun.

 

[Ed Ames]

OK, next question: is there anything I should do now to ensure my fix holds?

I'm tempted to take the trigger guard off again, smooth and polish it, and try a diy case hardening if I can find small amounts of suitable charcoal. I have an itty bitty little furnace (intended for melting glass and precious metals, not ideal for the job but I have it) and could make a crucible. Not for any good reason except to see what happens.

 

[jamesinalaska]

To be honest, any person using a TIG machine to "add a dab" of metal to a surface is pretty much already knowledgable about metallurgy. As you described them, I'm sure your repairs were just what was needed. As far as the Do-It-Yourself casehardening, I would advise not. You said yourself the trigger part you added the dab of metal to was cast, and for less expensive rifles as you've described that cast metal is typically an alloy and could include very soft metals with low melting temperatures such as zinc. The metal you added to the cam with your TIG welder is probably harder than the parent metal already. Polishing the parts with a dremel tool and some polishing compound is about the most I would want to do on any cast alloy parts.

 

[Ed Ames]

To be honest, any person using a TIG machine to "add a dab" of metal to a surface is pretty much already knowledgable about metallurgy. As you described them, I'm sure your repairs were just what was needed.

The biggest chance I see of a "should have done it another way" is that maybe there is another surface (other than the notch in the barrel lug) that should have been adjusted to change how much the hinge closed or something. However, I looked for that. Everything seemed to be tight and there weren't any gaps I could see to close. Doesn't mean I knew what to look for though.

As far as the Do-It-Yourself casehardening, I would advise not. You said yourself the trigger part you added the dab of metal to was cast, and for less expensive rifles as you've described that cast metal is typically an alloy and could include very soft metals with low melting temperatures such as zinc. ...

Good point. The trigger guard is ferrous (magnet test), so probably not a low melting point alloy but I don't know what to test for beyond that to see if it is amenable to case hardening.

 

[wally]

If it was "collectable" you've clearly done evil.

OTOH, if you got it to shoot and it didn't work before and does now you've clearly done good!

If you've "fixed" it before actually shooting it you may have had no effect, but if it doesn't work now its all on you.

Please follow-up and let us know how it goes.

 

[Ed Ames]

Not collectable. And it works!

 

[wally]

And it works!

It is very gratifying to fix things!