Question on Grip Screws

[sheepherder]

I drilled & tapped three holes in a piece of scrap steel today...Using the following taps & drills

Tap/Drill

3/16" x 30/#23

3/16" x 32/#22

#10 x 32/#21

(The two 3/16" taps obtained from www.tapsndies.com; the #10 is from Ace Hardware)

Pics below...Both the 3/16" x 30 & the 3/16" x 32 tapped holes accepted a Luger grip screw...(off an S/42 Luger)...The #10 x 32 tapped hole would only allow 2 threads of the screw before binding...The two 3/16" tapped holes allowed all 3 threads of the grip screw...

I ended up tapping my grip frame with the 3/16" x 32 tap...The Luger grip screw fits just fine...