Thompson grip mount

This is a drilling jig and template for making a type 1 Thompson grip mount out of 1/4" plate and 5/16" socket head cap screws. When using the horizontal grip, the mount is completely hidden.

The template was glued onto 1/4" plate with gluestick. The holes were drilled. It was rough cut to shape. A belt grinder was used to get close to the line. Then it was filed to the line, checking the fit with the grip.

The sides were milled down to 1/8". A mill isn't needed. It could be ground and filed.

For the retaining tab a screw was plug welded on and the head cut off. The sides were filed down until it fit the receiver. The back was filed until the mount could be fully inserted. The top was filed down until it cleared the barrel threads. Finally, the front was filed until it was flush with the receiver.

The jig was screwed into the front hole with a 5/16-18 screw. Then the angled hole was drilled with a 5mm bit. For original hardware the hole should be tapped #14-24. I chose to use m6 socket head cap screws. M6 screws do thread into #14-24 threads so m6 is a very close alternative.

A 5/16-18 socket head cap screw was cut down to less than 1/4" and plug welded in the front hole. On mine the head just cleared the barrel. If it interferes with installing the barrel, it will need to be trimmed.

Finally, the rear hole was drilled and tapped for a 1/4-20 set screw. A m6 screw could also be used. This isn't necessary if the mount snugly fits the receiver.

This is the drill guide that I used with the jig. A steel guide is needed. The Fusion 360 file is included so it can be adapted for other guides. https://www.amazon.com/gp/product/B07QVKPSHX/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Category: Hobby