Lyman GPR Lock Q...?

[NorthCoastBigBore]

I built one of these in .54 about 26+ years ago, gets used every year a fair amount, so I'm pretty familiar with that vintage. Happy with it, it's always worked.

I was just given another Lyman GPR, quite a bit newer (in .50, but that doesn't matter). I'm not sure what year exactly, but from what I understand, it's probably 5-10 years old. I just got it out today for the first time.

The Problem: The half-#### on the "NEW" GPR sets just clear of the nipple. Can't decap or cap with the hammer in that position. So I have to cap on full ####, which I really don't like.

I pulled the lock (I should have taken some pictures) and it looks like that is where this lock is intended to sit on 1/2 ####, which makes no sense at all.

The rifle (I'm told) has never been fired before I got it, and everything looks clean, tight and unmolested. No mashed up screw heads, drift pin marks, dings, file marks, rust, or anything like that.

The Question: Anybody experienced this in a GPR? Any solution? The locks are coil spring with a fly, I'm not seeing a way to assemble it "wrong" and still have it work otherwise, but maybe...? I've certainly considered milling or filing another notch for the sear to set in but I figure I'll ask before taking that route.

Any insight is appreciated...

NCBB

EDIT: I should have googled this first, looks like a know "flaw" in the design. I'll let the question stand though in case some enterprising shooter has a confirmed fix.

My 1991-ish GPR certainly does not have this issue...

 

[Rdrash]

Can’t say for my gpr as it’s a flint but my Lyman trades rifle I can put a cap on in the half #### position.

 

[NorthCoastBigBore]

Can’t say for my gpr as it’s a flint but my Lyman trades rifle I can put a cap on in the half #### position.

Same with my first one, any idea when yours was made? Might go looking for an older lock if this one cant be safely modified

 

[mooncoon]

A sear is a relatively simple thing to make. If you made a new sear which was longer from the pivot to the engagement, it would be the same as moving the half #### and full #### notches to allow more travel of the hammer. There is a qualification however; the hammer and tumbler must be able to rotate farther back ; something you need to check first. If you are making a sear, you need to use a piece of steel which can be hardened such as drill rod and you also need a source of heat enough to heat the metal red hot and in the case of drill rod, to allow you to hammer it flat from round then bend into an L shape and after final shaping and fitting, to temper it. Re tempering; heat the metal red hot, quench in water, polish a bit and reheat to brown.

It is also possible but probably faint hope that you might find a sear for another lock, in a gun show, which can be ground and shaped to fit your lock

after writing all of the above, are you able to heat the hammer red hot and bend it back a bit? that would be the simplest fix. Put the hammer in a vice and heat red hot in the neck area then use a crescent wrench upside down and hooked over the hammer nose to bend back a little. Ie the nose of the hammer goes through the eye in the handle of the wrench

cheers mooncoon

 

[NorthCoastBigBore]

A sear is a relatively simple thing to make. If you made a new sear which was longer from the pivot to the engagement, it would be the same as moving the half #### and full #### notches to allow more travel of the hammer. There is a qualification however; the hammer and tumbler must be able to rotate farther back ; something you need to check first. If you are making a sear, you need to use a piece of steel which can be hardened such as drill rod and you also need a source of heat enough to heat the metal red hot and in the case of drill rod, to allow you to hammer it flat from round then bend into an L shape and after final shaping and fitting, to temper it. Re tempering; heat the metal red hot, quench in water, polish a bit and reheat to brown.

It is also possible but probably faint hope that you might find a sear for another lock, in a gun show, which can be ground and shaped to fit your lock

after writing all of the above, are you able to heat the hammer red hot and bend it back a bit? that would be the simplest fix. Put the hammer in a vice and heat red hot in the neck area then use a crescent wrench upside down and hooked over the hammer nose to bend back a little. Ie the nose of the hammer goes through the eye in the handle of the wrench

cheers mooncoon

Well now bending the hammer is a simple idea that I have had to do before but totally missed when I was thinking about this. Probably the easiest, simplest and most efficient fix isn't it?

Thank you sir!