I own two models, MK9 and K40 - the latter just obtained in the last one month.
Both firearms have had the screws in the grips loosen and I have had a screw fall out while shooting, which is not a good thing!!
The tech. folks at Kahr have recommended Loctite (blue). anybody have a similiar problem and if so what was your solution?
Hmmm, first I've heard of that. I shoot my K9 a lot and with +P and +P+ loads and haven't had the screws loosen so far, although I do remove and replace the grips with each cleaning, so maybe I'm putting a screw driver to mine more often, don't know.
Are you using the hogue rubber grips or wood replacements?
A couple of solutions, besides loctite blue to consider. Simple clear nail polish on the threads or replace with a set of hex head SS screws, I think they're available from Brownell's.
Have you mic'd or used a screw thread and pitch guide to check yours? How about on the threaded holes of the grip frame?
Edited to add -
A check of the Kahr catalog shows replacement grip screws to $1.00 each, for a price comparison.
FYI: Contacted Brownell's, spoke to my gunsmith, and previously had contacted Kahr's tech folks - all three recommended Loctite (blue) for loose screws