Thompson Lock Question

[MissouriCrowinMass]

The attached photo show the lock from a Thompson Center Hawken Pistol that a friend gave to me. It's a beautiful pistol and I'd like to get it working perfectly. The hammer fails to 1/2 cock or cock.

I think the reason is that there's no spring or other mechanism to push down on the end of the sear and rock the other end of the sear up into lock where it would hold the hammer?

I've looked at many other locks and most have a "U" spring on the far end of the sear.

Can anyone help? Or explain to me how this lock is intended to work? I've tried finding a photo of it but failed. T/C has discontinued the Model from 1973.

Thanks,

MissouriCrowinMass

 

[Acorn Mush]

Looks like you have a lock from Thompson Center Patriot pistol. The part you have indicated via the arrow is a spring-loaded plunger that puts pressure on the sear to engage the half- and full-cock notches on the tumbler. If the hammer only falls to half-cock, that means that the "fly" a small wedge-shaped part that pivots on the tumbler, is stuck in the rearward position or is missing. I can't tell from your picture which is the case. The function of the fly is to allow the nose of the sear to override the half-cock notch when the hammer falls. If is a critical part in locks that are used with double-set triggers.

The fly is a tiny, easily lost part and your lock wouldn't be the first one to have it missing. Can you post another picture showing just the area of the tumbler and the nose of the sear? We may then give you better advice.

Hope this helps.

p.s. That is a REAL GOOD FRIEND you have. Patriots are good pistols and are getting hard to come by.

 

[Acorn Mush]

MissouriCrowinMass, on further study of the picture you posted it appears that the fly IS in place on the tumbler, and is held in the rearward position by the sear nose as it normally would be when the hammer is drawn from the fired position to the half-cock position. Check to see that the fly pivots freely, and that there are no chipped areas on it or on the nose of the sear.

Good luck.

 

[Loyalist Dave]

Does this occur when the lock is removed, or only when the lock in in the pistol?

LD

 

[Chawbaccer]

Why not contact TC and see if they will honor their life time warranty. Probably kind of iffy on the Patriot, but worth a look see.

 

[MissouriCrowinMass]

All You Guys - Thanks very much. Don't know where to start but here goes:

1. The guy is a GREAT friend.

2. The fly is free & loose. I can make the lock 1/2 cock & full cock great but I have to be holding it in my hand outside of the pistol and putting downward pressure on the back of the sear with my pinkie.

3. It looks to me like whatever was in the design to push down on the back of the sear is missing?

4. That "stop block" above the back of the sear hits has a nipple with a hole in it? If there was a "plunger" type spring there the pistol would work great.

5. I'm going to take your advice and call T/C even though the Hawken is not supported. I might get lucky?

Plan B is to keep checking out Gunbroker & E-Bay. No luck so far.

Thanks,

John

 

[madcratebuilder]

I agree with Acorn Mush. Lube the spring and plunger above the sear arm and lube the fly pivot. The fly should drop down and block the half cock notch when you go to full cock. After the hammer drops it pivots out of the way while your cocking, so you can engage the half cock notch. As you continue to full cock it should ride over the nose of the sear and block the half cock for firing.

 

[Acorn Mush]

MissouriCrowinMass, here are a couple of pictures so's you can see if you've got all the parts you need to get your lock operating correctly. Be sure the sear screw is not overly tight. The sear should pivot easily.

This shows the sear, the plunger, and the plunger spring. (I don't know if T/C calls it a plunger or not.)

[/IMG]


Here you see the above-mentioned parts and the hole where the plunger and spring mount.

[/IMG]

Sure hope this helps you solve your problem. Don't despair. There's lots of guys here who will help you get 'er fixed!

 

[MissouriCrowinMass]

Acorn,

That picture was exactly what I needed to see. I didn't know that was a spring loaded piston! Got the T/C Hawken working perfectly.

Great help!

Great Forum!

John

 

[Acorn Mush]

Missouri,

Happy to be of assistance. This IS a great forum.

In case you want to shoot your pistol, here is a link to the online manual from Thompson Center:

http://www.tcarms.com/assets/manuals/noncurrent/Patriot_Supplement.pdf

 

[mykeal]

Well done.