Converting Mounts to 8-40

Morning Guys, and happy new year!

I have an action that has a scope base screw stripped out, so I was going to convert it over to use 8-40 screws. I was wondering if anyone had info on drill bit size to use for the action, but also to enlarge the hole in the bases, both for the larger shank of the screw and the larger diameter of the head.

Here are the screws and tap I found on Midway:

http://www.midwayusa.com/viewProduct...tNumber=110607

http://www.midwayusa.com/viewProduct...tNumber=233454

Thanks!

Adam

drill size #28 is for the 8-40 theads ,not sure on the screw heads

The plug tap works if the holes go all the way through receiver. Need a bottom tap if holes are not all the way through, or if you don't want to remove barrel to tap the front hole. I believe the screw heads are the same size. #28 drill bit as already suggested.

Thanks for the help guys!

Cowboy howd you make out with this exercise?