Uncle Mike's Magizine cap stud
 

I bought the Uncle Mike's swivel studs to mount a sling on my Remington 870 shotgun. I as going to modify my magizine cap to accept the stud but I lost my instructions that tell me the tap size.

Does anyone know the tap size I need to accept the screw?

RE: Uncle Mike's Magizine cap stud
 

If You've got a hardware store close just take it there and size it up. Could be a 8-32 or10-24 threads who knows, hopefully not a funky metric size. Once you find out what the thread size is then you can figure out what tap you need.

RE: Uncle Mike's Magizine cap stud
 

So no one has made this modification before? I know it was in the instructions that came with the swivel, but I lost the dang thing.

RE: Uncle Mike's Magizine cap stud
 

Why don't you just buy the Uncle Mikes 870 cap with the stud already installed in the cap?

http://www.uncle-mikes.com/products/remington870express.html

If you feel that you must drill a hole in the cap then you drill it slightly larger than the unthreaded part of the shaft and use the supplied nut on the inside of the cap with some loc-tite and a center punch to keep the nut from unscrewing from theswivel stud.

RE: Uncle Mike's Magizine cap stud
 

Its a number 3 drill bit with 1/4-28 threads if your going to drill and tap the swivel stud. If you use the internal nut thats a 5/16" hole.

RE: Uncle Mike's Magizine cap stud
 

Yes, I've done a number of these. LIke I said you have to determine the correct thread size of your stud, use the right drill bit to drill your hole, then use the tap to cut the threads. I've found it easy if I have a unknown size of bolt/thread size to go to the hardware store and match it up. There is so much stuff coning out in metric sizes it's hard to tell sometimes. Then I know for sure of the size of the drill and tap I need. It's not rocket science......Good Luck

RE: Uncle Mike's Magizine cap stud
 

http://www.uncle-mikes.com/products/magnum_most_pumps_auto.html

If this is the set you have. Which is the generic for "most pump and auto" according to uncle mikes website. It IS a #3 drill bit and it IS a 1/4-28 thread tap!!!

RE: Uncle Mike's Magizine cap stud
 

Thank you deke appreciate it.