Kahr 9mm and .40 Magazines the Same?

[Ninjatarian]

I was looking at the mags from my K9 and PM40 the other day when I noticed how similar they were. Same exact dimesnions it seemed. So I tried popping some .40 rouns in the 9mm mag and they fit exactly how they did in the .40 mag. Went to the range, popped off a couple 9mm mags loaded with .40, no problems.

Are they the same mag, just stamped with different markings? If so, why even bother with different stampings? Why not just do it how companies do .40 & .357sig and mark it "9mm & .40" ?

[wyntrout]

They "seem" to be the same size, but I found the .40 tubes were a few HUNDREDTHS wider in the top of the magazine. I tried using my old K9 7-round mags as 6-rounders... tried widening at the top of the tubes and between the feed lips... unreliable in my P40. I finally gave up. I experiment a lot with magazines and have ruined a few. I bought 5 new followers for my .40 mags after I seemed to have smoothed the metal pin a bit too much... stopped locking the slide back on empty mag. I should have bought one or two more... I have three 6-rounders with metal base plates and four 7-round extended grip mags for reloads or the range. I have to put 15/16" O.D. O-rings... 3/32" diameter... to stop the flush-fitting metal base plates from pinching me, though. 1/8" was too big... caused feed problems. I want the slightly shorter grip/flush mag for CCW. It's a bit longer in the grip than my PM9.

Wynn

[Ninjatarian]

I must be a lucky guy with my PM40. My flush mount mags do in fact fit completely flush with the bottom of my grip, no gap at all, and the 9mm mags worked like a charm 100% unmodified. You say the .40 mags are a few hundredths wider at the top, how much variation is there from .40 mag to .40 mag (or 9mm to 9mm)?