I just got a P239 with both barrels-357 Sig and 40. Am I correct in assuming I can load 357 Sig in a 40 mag but not the other way around?

*****I apologize, I was speaking to my P229s and P226s and Glock 32c. It does appear that SIG does differentiate between 40 and 357 in the P239 magazines.*****


For P229 and P226 mags SIG marks their magazines 357/40. That mag works for both calibers.

You may have confused that early Glock 40 mags can have problems feeding 357.

I have both 357 and 40 Sigs and Glocks.

This message has been edited. Last edited by: John3200,

No.....a .357 sig and a .40 cal mag are actually the same because a .357 sig is a .40 cal round necked down to fire a 9mm bullet

SIG marks p239 mags 40 or 357. You are correct. 40 will not go into 357 mags however.

Congrats on an awesome pistol btw

quote:

Originally posted by SigSentry:
SIG marks p239 mags 40 or 357. You are correct. 40 will not go into 357 mags however.

This, I had a 239 357 and mags were marked 357 only. Unlike mags for 320, 224, 229 and 226 which are marked 357/40.

I had tried it both ways and I chambered a 357 from a 40 mag without a problem. I got exactly one round of 40 in a 357 mag and that was all it would take. I will be shooting it for the first time tomorrow.

It's a CPO dated 2015 and it is immaculate. My guess is that it is a 2007 based on serial number. Only a few rounds went thru it since the CPO job from the looks of the barrel smiles.

Are the CPO's all police and gov't guns?

The P239 357 marked mags usually have a taper in the front of the magazine.

Too lazy to search for pictures but if you have both magazine types look along the front. You'll see the difference why you can't fully load the 357 mag with 40

Sig went to the trouble of building two different magazines and says .357 mags should be used with .357 ammo. However, many, many, many people successfully shoot .357 (and 9mm) from .40 mags.

.357


.40

I thought I read someplace that the design of P239 magazines had been changed to eliminate the internal ridge of the 357 SIG variety so 357 and 40 S&W mags are the same now. But if not, and certainly originally, 357 ammunition can be loaded in P239 40 magazines and they will evidently function normally, but the reverse is/was not true: 40 ammunition cannot be loaded in P239 357 mags.

Note that this difference is/was true only of P239 magazines. There is no difference in 357 and 40 magazines for P226s or for P229s. People who are familiar with only the 357 and 40 P226 or P229 may be forgiven for believing that’s true of the P239 as well, but at one time at least it wasn’t.