Thompson Center question

[Hank in WV]

I was just looking at one of Russ' TC rifles and am curious about something. It's a .58 Big Boar and at the very back of the barrel on the top flat, there is a small screw that looks to be a set screw. It doesn't appear to do anything. Does anyone know it's function?

[Ohio Joe]

Hank, I believe that is for mounting a rear Hunter's Peep Sight. I believe (if I remember right) some guys had a small TC Peep sight mounted to their TC tang. Of course I haven't seen this application for many years, but I believe it is very similar to the Lyman's GPR peep sight set up. 

There is a picture of one (EP0302) in the 1997 Dixie Gun Works catalog (yes, I seldom throw any old catalog away) and it says it's for the current TC Hawken, one hole is required to be drilled and tapped.

[Ohio Joe]

Hank, I believe that is for mounting a rear Hunter's Peep Sight. I believe (if I remember right) some guys had a small TC Peep sight mounted to their TC tang. Of course I haven't seen this application for many years, but I believe it is very similar to the Lyman's GPR peep sight set up. 

There is a picture of one (EP0302) in the 1997 Dixie Gun Works catalog (yes, I seldom throw any old catalog away) and it says it's for the current TC Hawken, one hole is required to be drilled and tapped.

Disregard my above post. I just went down to my gun room and looked at my old TC Hawken and I see the screw you're talking about, Hank. I don't know why it's there? I'm pretty sure it has nothing to do with the sight I was talking about. Sorry...

[Semisane]

That hole is for mounting a scope base that TC used to make. It was offset a bit to the left so the hammer would clear the scope and was mounted to the barrel using that screw hole and the one for the rear sight. As I recall, the TC stock number was 9930.

[Fyrstyk]

I have used the hole in the breach plug of my T/C to mount a Skinner Peep sight.  I have 2 barrels with this set up.  It works great for those of us with aging eyes.

[Hank in WV]

Thanks guys, I suspected it might have something to do with sights but I wasn't sure. I've never noticed that screw before.

[Uncle Russ]

There are actually two things on the barrel I don't have a full grasp on...one is that screw hole as discussed above.
The other appears similar to a plug with a "ping" mark, on the left side of the barrel directly across from the snail located on the right side.
I will try to post a picture.

Uncle Russ..

(click on the picture to enlarge it....very poor picture, I will take it outside for a better shot.)

[Uncle Russ]

This is the screw-hole as previously discussed.

Uncle Russ...
(click on the picture to enlarge)

[Semisane]

There are actually two things on the barrel I don't have a full grasp on...one is that screw hole as discussed above.
The other appears similar to a plug with a "ping" mark, on the left side of the barrel directly across from the snail located on the right side.
I will try to post a picture.

Uncle Russ..

(click on the picture to enlarge it....very poor picture, I will take it outside for a better shot.)

I don't know for sure, but I've always assumed that mark is left by the jig that holds the snail to the barrel for welding.

[Uncle Russ]

Hopefully this is a better picture of the "mysterious" plug on the tang of the .58 Big Bore barrel.

Uncle Russ...
(click for a better picture)

I think Semisane may be on to something with that...this picture is a bit more clear but certainly doesn't explain "why"!