357sig conversion to 40s/w

Never heard of that issue. Somewhat related, I changed out springs in my old G23 mags and all three had slightlly different followers. The magazine has the most issues (doesn't eject with any "umph", if you will) is the one make LE only. I didn't know the mags were different.

 

Welcome to the forum jlarson1980! I hope you enjoy yourself here.

 

Welcome Jlarson! Enjoy the forum!

 

I've never heard of this issue either and it makes zero sense; the .357Sig is just a necked down .40. The only difference between the magazines should, literally, be the markings. How old are these magazines? What follower # do they have?

Updating to current followers is as easy as disassembling and reassembling the mags, but you shouldn't have to. Unless you just have older magazines or weak springs, you shouldn't need to do anything. As of the last time I checked, Glock was on the #8 follower for .40, so there have definitely been some tweaks over the years.


As far as the old "law enforcement only" mags, those haven't been made since at least 2004 and the majority are going to be older, possibly going back to 1994. Those magazines can't be updated past follower # 5; Glock redesigned the interior of the magazines, I forget exactly what they changed, but the redesign started with follower #6.

 

I never noticed this until I changed the spring. The magazine is stamped 9/94 and has follower #5. The others are follower #6. Interesting stuff.

 

The magazines are not the same between calibers. The inner dimensions of the magazine tubes are different, as are the followers.

You could try some .40 #8 or #9. followers in the 13-round .357SIG magazines, but it may be better to buy separate .40 magazines so you don't have to switch followers between magazines every time you switch barrels, you can just use the different magazines.