No.4 (T) Mounting Threads

When I purchased my T about ayear ago, the scope was shipped separately and I noticed that the rear mount wenty on hard. I have shot it a good many times and am quite pleased. Tonight , I gave it the ol' scrub down and removed the scope . Now, I can't quite get it to screw on properly and am not about to force this old girl. It is obvious that the rear mounting screw thread is stripped at the very beginning and a simple rethread with the appropriate die is in order. My question is what is the thread ( I'm sure it isn't your pedestrian variety), where can I get one, and if I can't, can I get it repaired. Any help would be appreciated.

They are called 4BA screws in the reference books. It is an archiac British specification thread. The holes in the pad are 0.15" diameter if that helps.

When i was building my No.4 replica i bought the pads and tap for the mounting hole from a company called nodak spud. They no longer sell the mounts and pads but might be able to tell you what size tap was in their kit. You could then order the tap from any english machinist suppy store.

nodakspud home page.htm

Terry,

If I'm reading this correctly you're talking about the tapped hole in the rifle body for the rear mount thumbscrew?

If that is the case the threadform is 1/4 bsf. You should be able to pick up a tap at any good engineers merchant but if you can't they are an off the shelf item here in the UK.

If you don't mind me asking is the bracket an original or repro? If it is a repro the machining of the centres between the recess for the front pad spigot and the rear pad would only need to be a couple of thou out to make it a tight fit.

Hope this helps.

Cheers,
Simon.

Quote:

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Originally Posted by TerryChambers

When I purchased my T about ayear ago, the scope was shipped separately and I noticed that the rear mount wenty on hard. I have shot it a good many times and am quite pleased. Tonight , I gave it the ol' scrub down and removed the scope . Now, I can't quite get it to screw on properly and am not about to force this old girl. It is obvious that the rear mounting screw thread is stripped at the very beginning and a simple rethread with the appropriate die is in order. My question is what is the thread ( I'm sure it isn't your pedestrian variety), where can I get one, and if I can't, can I get it repaired. Any help would be appreciated.

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The bracket is original and it appears that it is the rear thumb screw that is slightly stripped. As I say it went in a year ago with some VERY gentle manipulation and I am sure it will again but it needs to be cleaned up. Thank you for the help.

I have dealt with a couple of No4T's in my life. You ought to clean out the 1.4" BSF body thread then use a die nut on the thumbscrew thread. It that fails, you need a new thumbscrew, I have never seen a body thread strip

Ask me if you need a couple of new thumbscrews to try. Sorry, but only have genuine originals.................

Terry, PM me if you'd like to borrow a tap.