Thompson Center Hawken Hammer problem

[bkct]

I'm working on a very abused TC Hawken 50Cal that I picked up. The gun is in rough shape and had something clogging the barrel. After using a grease gun as suggested here I solved that issue. On to the lock which the hammer would not cock. After looking at youtube I took the lock apart and got the lock plunger working. Now the hammer works smooth stopping at half cock and full cock. If I use the main trigger the lock works perfect. But if I cock it and use the set trigger then pull the trigger the lock stops at half cock not going all the way. Any ideas as to what is wrong? Seams like it should be a simple fix but I am not that familiar with these things.

 

[Walkingeagle]

There is a little tiny part in there called a fly. Its job is to swivel into place and block the half cock notch. I suspect you installed it incorrectly or completely left it out upon reassembly. It’s a tiny piece so look carefully for it.
Walk

 

[Grenadier1758]

yYou are missing the fly in the tumbler. The fly is a tiny metal piece that fits in a slot in the tumbler over the half cock notch. When you fire using the set trigger, the sear rides on the tumbler. The sear encounters the fly and moves the fly over the half cock notch and lifts the nose of the sear over the notch. When you fire unset, your trigger finger lifts the sear over the half cock notch.

Thompson Center Muzzleloaders Hawken Parts (gunpartscorp.com)

Its listed as out of stock, but you can see how small that part is.

Looks ass if RMC Ox Yoke may have it. I think the Lyman fly is virtually identical. RMC has an outline diagram of the lock.

Lyman Lock Repair Parts – RMC Ox-Yoke Muzzleloader Supplies

The fly is part 53 and is hidden under the bridle, part 49.

 

[bkct]

Looked it up and it's missing. Don't recall it being there. Can a Fly be purchased for that lock?

 

[painter]

Lock

 

[Grenadier1758]

Look at the illustrated diagram above.

 

[Walkingeagle]

Cam be purchased, yes. Try The Gun Works Muzzleloading Emporium in Oregon.
Walk

 

[bkct]

Thanks Guys. I love this forum, very helpful.

 

[ohio ramrod]

If you order a new fly, get two. They are easy to drop and hard to find. I have had one somewhere on my shop floor for over twenty years!

 

[Zonie]

The best way to find a missing fly is to use a very strong magnet. Move it all over the area where the fly might have fallen and then move it all over the areas where the fly couldn't possibly be. Chances are it is in the "It couldn't possibly be there" area.

In any case, the strong magnet will pop it out of its hiding place. I use a Radio Shack 8" speaker for the magnet. The magnet on it is about 2 1/2" in diameter.