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AR15.COM
4/26/2026 6:35:25 PM EDT
I have a P229 in .40 S&W I just put a OEM .357 barrel in . Just wanted to have some versatility come the next ammo shortage, etc.

I have several factory Sig mags that hold 12 rounds of .40, but when I went to load them with .357 with my Lula loader I got 15 rounds in. Not that I’m complaining at all, but my confusion comes from the reality the case diameter is the same (not the neck of course).

Anyone care to explain? (Nice problem to have)
4/26/2026 6:50:40 PM EDT
[#1]
.40 and .357 sig rounds are same body diameter.  

4/26/2026 6:57:50 PM EDT
[#2]
You shouldn’t have. Original capacity for 9mm was 13. Only fairly recently have they been 15. No way you should get 15x .357
4/26/2026 7:01:00 PM EDT
[#3]
Quote History
Originally Posted By BuddyChryst:
You shouldn’t have. Original capacity for 9mm was 13. Only fairly recently have they been 15. No way you should get 15x .357
View Quote


I couldn’t believe it either. They went in fairly easily. I know they’re not “supposed” to , but damned if they didn’t.
4/26/2026 7:01:48 PM EDT
[#4]
Quote History
Originally Posted By 18B30:
.40 and .357 sig rounds are same body diameter.  

View Quote



Exactly, I stated as such in my original post.
4/26/2026 7:55:45 PM EDT
[#5]
Yes, so no way you can fit 3 more .40 cal rounds inside, unless you are Dr. Who and the Tardis is now a Sig P-229 magazine.
4/28/2026 12:26:19 AM EDT
[#6]
The only way you could get that many more rounds was if you were putting 9mm rounds in the .40 S&W magazine!
So... I find comfort in the fact that if Trump has to work so hard to go to Heaven, then there is a shit load of Democrats that have no f-cking chance to go anywhere but HELL. Sometimes it is entirely appropriate to kill a fly with a sledge-hammer.

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