I've had experience with multiple Kahrs over the last decade.
MK9s, K40 which have been solid, lucky for my first purchases.  Just make sure you have the right dovetail sights as two dovetail specs exist with old vs new stock.

Eight years ago I went ahead and tried the P40 with this experience + good test firing proficiency thanks to the graces of a neighboring shooter at a range.
My P40: Had multiple failures to feed and eject with federal/Win/Rem ammo. Sent to factory under warranty on my dime, $30 ish, returned with same issues but I also noticed the front frame rail had busted away. Resent to Kahr under warranty, paid $30, waited for it to be fixed 100%. Again same issue but they didnt repair the frame, but rather filed away at cracked spots, just leaving the rear and dust cover metal insert rails intact as before. Sold at a loss.Same time the P40 was picked up, I also had bought the CW45 which has not had any issues.
Skip ahead six years ago -- couldnt resist giving the CT40 a shot on a PSA daily deal sale. Stuffed it in the safe and forgot about it with work, hectic life.

Went ahead to try the CT40 out  with recent turmoil brewing. Cleaned well in advance with CLP. Using speer lawman ammo, I had frequent failures to feed ammo and eject. Stopped afted 3 mags in, about 25 rounds. Giving it a field strip at home, I noticed a few things.

1)  The slide stop was gouging the slide under the left side.
2) The slide closed on an empty magazine, as the follower didnt support the slide stop well, and the slide stop fails to fully catch into the slide due to poor magazine follower support.
3) Told Kahr, they said I have to pay for repairs as warranty eclipsed given the issue came up past 5 year warranty interval, I tell them off for not supporting an otherwise brand spanking new gun, and then they offer a one time courtesy repair for minor items with shipping on me.
4) Weapon placed on consignment for someone else to figure out.

Gouged slide from slide stop:
Attached File


Poor magazine follower support, leading to failure to open back on last round. Here, the slide is pulled back on a empty mag. The slide stop doesnt fully engage the slide cut out.
Attached File


Magazine follower -- flimsy magazine follower skirt doesnt yield great support to have firm slide stop contact by the metal follower tab. Lakeline LLC makes an aluminum follower just for this issue. Equals pricey mags with more add ons for ?? Questionable reliability.
Attached File

Must be one of the lucky ones!
A family member had similar problems with a P40.
So a total of 3/3 Poly Kahr 40s with significant issues using American mfg'd/no reload brass cased ammo. And significant cost sending back to the mother ship and spendy single stack mags.

Only recently converted to Glock, and havent been happier.

I guess they are just hit or miss. My 4 have been good.

My K40 Elite was flawless. It sits retired in the the safe for now.

My CW9 was flawless. I didn’t care for the magazines as they’d dump rounds in my pocket, sold it and bought a Shield 9mm when they first came out.

Bought a PM9 in Summer of 2020. My carry rotation was either a pocket carrier 642 in the winter or a pocket carried LCP with the 7 round mag in the summer. The riots in a nearby city had me second guessing that choice. I use Mag Guts followers with 7+1 in the gun and a 7(converted to 8) round mag as a reload. 16 rounds of 9mm beat the pants off 15 rounds of 380. The PM9 is much easier to shoot than the LCP, but also much easier to carry than the Shield. I bought a 2nd PM9 last winter as it’s become my primary carry gun. I need a few more mag guts sets.

Here's the frame rails on my PM40. It's currently back with Kahr. The "tech" tried to tell me it wasn't a real issue





ETA: I've already had to replace the slide stop, as it had worn out and no longer functioned as a stop. It did stay in and keep the slide from flying off, though

That's rather disappointing.  I had a pm9, but probably only put 6-700 rounds through it before I sold it.  Like the size and feel, but it "felt" a bit "cheap".

Issues like these keep me from jumping on the silly cheap ST9.