Pm40 ?

So I have decided to break in my PM40. I have a smooth running CM9 and I did the suggested prep as I did with the 9. I racked the PM40 200x cleaned and lubed it.

2 Idiosyncrasies

1. When I use the slide stop to release the slide the slide moves forward then stalls for a second then goes into battery. (Both mags)

2. One of the mags will not hold slide open.

any ideas ?

Best to call customer service and see what they say.

My new PM40 didn't do either of the things you mentioned.

It could cure itself with a some rounds fired. Firing rounds is far more productive than hand racking.

Watch the barrel hood, top front for signs of peening. Haven't heard of that for many years but my K40 did so which required a new top end which Kahr replaced without question.

Could just be a snug tolerance and will loosen up.

I always thought Kahr recommended firing 200 rounds as a break in -- not racking 200 times. Firing 200 rounds would exercise more parts of the gun and under greater stress.

My PM40 worked ok right out of the box, but I need to put more rounds through it to feel it's ready to carry.

FWIW: When I got my CM9 First thing I did was take it down, hit all the appropriate lubrication points with a small paint brush and good gun grease. Reassembled then put on a pair of leather gloves and RACKED it... a bunch. 100, 200...somewhere in that range, not 10 or 20.
Took it to the range with my own mild reloads, and a couple boxes of full house military fmj rounds. At first...it didn't like my mild reloads. Had a couple of malfunctions. The little gun did just fine with the military fmj's however. Towards the end of that session, somewhere around 150-200 rds I found that even my mild reloads were running just fine, and have ever since. There was definitely some sort of "break-in" going on. EVERY time I shoot the gun, cleaning involves taking it down again...pulling the barrel and going through the whole procedure of removing fouling and old grease then starting over with new.
It's somewhat of a P.I.A. I suppose but these little Kahr handguns are sort of like the Lambourghini's of the handgun industry and "Kia-level" maintenance ain't gonna cut it.
Besides...everytime I slip my CM9 into the JIT holster and step out of my home..I'm betting my life that it will work as designed.

I have a new PM40 and have had mixed results. I have had it out to the range twice now. The first time I fired 200 rounds of store bought 180 grain with limited issues. This past week I took out reloaded Poly coated lead at 140 grain and had nothing but issues. I loaded at the minimum powder wise, and was unable to tell if they just needed more umph. I had issues going into battery, ejecting, and everything above the sun. I loaded more tonight with 5.3 grains of Bullseye. I am curious to see if it was an issues of not enough powder, or the gun doesn't like reloads. I have a Sig P365, M&P 2.0 .45, Model 640 Smith, LCP 2, and have never had any issues with this type of ammo through any other platform.

Many Kahr's do not like reloads. Be sure to do the cartridge/barrel "plunk" test for bullet seating depth. (Schematics available under Sticky's.)
I have concerns reloading .40 S&W for the Kahr's due to the high pressure & possibility of seating bullet too deep to obtain reliable function. I would agree 140 gr. better reloading choice than 185 gr. for the Kahr.
I do reloads for the Kahr CW 380 and they run quite nicely.
I use .40 reloads in my S&W pistols; and use on sale .40's for my Kahr (1600 rounds- Black Friday from Academy @ $00.16 each after rebate).
In the case of the PM40, be sure not to forget the Isosceles and straight wrist stance.