291C driver, stripped rear cover screw hole

**Elitopus1** · April 13th, 2020, 08:44 PM

I have a pair of 291C drivers sitting on the shelf in my garage. I?m going to use them with GPA phragms to make some kinda 288H. Last time I took them apart one of the screws just spins when it should start to tighten. The screw itself is good, how can I fix the hole? Tap for a bigger screw? Some kind of Helicoil?

These drivers are very clean, and came with original phragms. I didn?t over tighten the screws, so I?m not sure how it got this way. Anyways, it?s been on my list of things to do for years now, and now I have the time to fix it.

**bowtie427ss** · April 14th, 2020, 07:29 AM

Since it's just a cover, i'd either try cleaning out the hole really well with alcohol and compressed air and then coating what's left of the threads with JBweld then chase with a bottoming tap after the JB is well cured, or i'd just whack it with a SHARP center punch 2 or 3 times around the edge of the hole.

Neither method is good for structural strength to any degree. But, either will be good enough to keep the cover and screw in place for many years.

I think your resale value will be better with matching cover screws than with one screw head that sticks out to say it doesn't belong.

All that said, if you can find an old retired machinist or gunsmith willing to make you a new, slightly over-sized screw, that will be the invisible remedy. But, it renders proprietary the screw for that hole.

**Elitopus1** · April 14th, 2020, 03:37 PM

Thanks for the suggestions Bowtie. Think I?ll try the JB Weld idea. Sounds like it would work, and not be noticeable.
And I already have the stuff needed to do it.

**Phil-G** · April 14th, 2020, 07:17 PM

helicoil.

**bowtie427ss** · April 15th, 2020, 07:44 AM

Originally Posted by Phil-G

helicoil.

Probably too small and shallow for most shops to install a helicoil.

He'd need to find somebody that could put in a KATO type tangless insert. Then, there's the cost.

By the time you pay somebody to set up and do the job, one would probably be further ahead to just source another driver without a stripped hole.

Again, it's just for a cover fastener. If it were of more structural importance, a solution that allows full and proper thread engagement would be the only answer.

**Phil-G** · April 15th, 2020, 10:30 PM

Originally Posted by bowtie427ss

Probably too small and shallow for most shops to install a helicoil.

He'd need to find somebody that could put in a KATO type tangless insert. Then, there's the cost.

By the time you pay somebody to set up and do the job, one would probably be further ahead to just source another driver without a stripped hole.

Again, it's just for a cover fastener. If it were of more structural importance, a solution that allows full and proper thread engagement would be the only answer.

i could do it.