I think I can do it

[bronko220002]

I have an Encore breech thread cleaner that I just used to practice on. Yes its plastic but I don't see an issue using my drill press. I have a press vise that will hold the BP securely in place. See photos.


First step was to drill out the .157" hole for the 10-32 tap.

Next tap the hole all the way thru and check with vent liner.
Lastly countersink .372" hole 1/4" deep for vent liner and install.

I'm wondering if I should go deeper with the countersink.

 

[jsteurrys]

Most are recessed.

 

[bronko220002]

Most are recessed.

That would be no problem. I'd just need to go a little deeper with the countersink. I think the plastic is actually harder to work with because it tends to melt even under a little drilling. I had to cut off the "burrs" with an exacto knife.

 

[sabotloader]

Good thoughts and a great follow through. You gadget should work just fine. You could have use a brass 10/32 screw also. I usualy you a brass tooth brush to clean out the treads.