TC flintlock tumbler

[foresterdj]

A friend sent his Thompson Center Flintlock to me to fix, if I could. I found that the half cock notch was broken off. I found a "replacement" at RMC Ox-Yoke, part number 8012007. My friend ordered it and had it sent to me, it arrived today. Has anyone ever used one of these replacement parts?

It is close, but different.

For one thing, the slot where the coil spring push arm goes and is held with a small roll pin is not there, instead a curved pocket. It seems like the end of the spring push rod might fit in there, held by spring pressure.

Real problem is the full cock notch, or lack of it. Where it should be there is just a tiny lip of metal, which does not catch the sear. See picture.



The original is on the left, red shows broken off half cock.
New is on right, blue shows full cock, such as it is.
Also, the yellow shows the machining for the fly, which seems different.

Is this "replacement" the correct part, maybe mismanufactured, or is it the wrong part for this gun?

[Leatherbark]

I just took off my TC Hawken lock and the tumbler is made like your replacement.  All of my TC sidelocks  just have a dimple where the mainspring plunger bears.  No roll pins that I've ever seen on a TC lock.

Bob

[foresterdj]

Thanks. In my research on this I have seen references to T/C having a 1st and then a 2nd generation lock, though never any description of what the changes were. Perhaps this was part of it. Back in the mid-'80's I was at a muzzleloader shoot at Ft. Benton MT with my T/C .50 Hawken (Indeed, how many got into the muzzleloading sport due to these rifles at that time) and my full cock notch broke off. Why I still have that broken tumbler in my gun cleaning kit is a mystery (I think I inherited pack rat genes from my Dad), but it was of the roll pin style.