Sideplate assistance needed

[Craig Wilcox]

Been doing a lot of adding things on to my build, like trigger plate, trigger guard, tang bolt.  And would love to add the side plate.  I have the top hole (goes through the tang) through the wood and all, and threaded into the lock plate.


But, before I drill the holes in the side plate, I would like to make the counter-bore for the heads of the #8 screws.


Does anyone have a source for a 3/8" counter-bore with a #8 stud or drill bit for centering?  I looked at McMaster-Carr, with negative results.  And a couple other machine tool type sites.

Thanks in advance.
Craig

[PrairieD]

Hello Craig! Check out The Yard Store in Wichita, KS --  www.yardstore.com -- and look under "Counterbores - Spotfacers" -- they have a 3/8" spotfacer that takes a 3/32" pilot

https://www.yardstore.com/consumables/countersinks/counterbores-spotfacers/counterbore-spotfacer-3-8-x-3-32

The Yard handles a lot of the surplus tools from Boeing/Spirit...

Mike C.
Pretty Prairie, KS

[davec2]

From McMaster Carr, purchase a 3/8" counterbore with a changeable pilot.  If you get the counterbore, part # (3102A14) for $25, and then do one of two options for the pilot.  Either get a smaller pilot than the 0.164 you need for a #8 screw (i.e. a 5/32" pilot (0.156"     Part # 3103A12) and under drill the side plate with a 5/32" hole until you get the 3/8" counterbore in place.  Then drill the 5/32" hole out to the 0.164 you need for the #8 screw.  Second option is to get a 3/16" pilot (part # 3103A13    0.187" diameter) and turn it down to the 0.164" you need and counterbore the side plate with that.  If you don't have a lathe, you can turn down the larger pilot by chucking it up in a drill press and using a file to reduce the diameter.  If you do have a lathe, or access to one, you can simply make your own pilot for the counterbore.  I make my own pilots out of brass and use these replaceable pilot counterbores all the time as I sometimes need a 3/8" bore around a clearance hole for a #8 or #10 or even a #12 screw....so I just change pilots.

[Mike Brooks]

Been doing a lot of adding things on to my build, like trigger plate, trigger guard, tang bolt.  And would love to add the side plate.  I have the top hole (goes through the tang) through the wood and all, and threaded into the lock plate.


But, before I drill the holes in the side plate, I would like to make the counter-bore for the heads of the #8 screws.


Does anyone have a source for a 3/8" counter-bore with a #8 stud or drill bit for centering?  I looked at McMaster-Carr, with negative results.  And a couple other machine tool type sites.

Thanks in advance.
Craig

Are you going to counter sink your sideplate/lock bolts?

[Craig Wilcox]

Thanks, guys - that should take care of the problem.

Yes Mike, I will counterbore and also reduce the head height a bit.  I do like the look of a counterbore.

[Mike Brooks]

Thanks, guys - that should take care of the problem.

Yes Mike, I will counterbore and also reduce the head height a bit.  I do like the look of a counterbore.

Most all lock bolts were not counterbored on American guns.

[Frank]

Never counter bore my side plates.

[Hungry Horse]

Counter bored sideplate screws are pretty much seen on cheap kit guns, rather than genuine antiques.

  Hungry Horse

[Craig Wilcox]

Well, I must not be an old dog - 'cause I am learning new stuff every day.  Y'all just saved me some money!

I will, however, decrease the thickness of the head on those bolts.

Many thanks!