I'm not sure which category this would go in but I'll try here.

So, I have a P229 non-railed, frame made in Germany. I have a bunch of mags, some not marked for caliber. Those not marked for caliber hold 13 rounds. The marked mags are marked.40/.357 and hold 12.

Not seeing any difference between the marked and unmarked mags, I put some .40 ammo in the 13 rounders and hand cycled them without issue. However, I wonder if these aren't actually 9mm mags since they are 13 rounds.

So, question is this. Is there a difference in the mag geometry between the two calibers since the .40 fed fine by hand ? The 9mm fed fine too. So, what gives with these ? Thanks.

Measure the widths of the unmarked ones and compare that to the widths of the 357/40 magazines. I will hazard a guess that the 357/40 mags are slightly wider and if so, the unmarked ones that hold 13 rounds of 9mm are for the P228.
(Assuming I understood everything you reported correctly.)

I'll check that today with some calipers. Thanks.

Odd that you don’t see any physical difference between the mags. The marked .40/.357 mags should be visibly wider at the bottom and taper narrower at the top third.

I am assuming you are determining the mag capacities by the witness holes and that the unmarked mags hold 13 rounds of 9mm, not .40 or .357, and should have straight sides. If the unmarked mags hold 13 rounds of .40, then I have no idea what kind of mags those are.

The non-marked 13-rounder could be some unknown aftermarket brand. Post pics of both next to each other, back view and side view, and that should clear up the confusion.

quote:

Originally posted by 12131:
The non-marked 13-rounder could be some unknown aftermarket brand.

Yes, it seemed odd to me that factory magazines would not be marked in some way.

I've learned to be very wary of any magazine that is not marked... either factory (is there such?) or aftermarket... it they can't put their name on it what does that tell you about how they feel about their product?

I've only known the .40/.357 Sig mags to hold 12 rounds and the 9mm mags to have 13.