I had my Glock 48 out today and ran into a bad mag. (I have lots of mags and just grab a random one when I go to the range, so chances are this is the first time this mag has been used).

-The gun is stock
-Only addition to the gun is a TLR7 sub.
-No optics (so not a screw/extractor channel issue)
-I am not limp wristing or likely causing the malfunction. Its not my first rodeo.
-Mag is stock Glock 10 round magazine.
-Mag catch is stock Glock plastic mag catch.
-Had another mag out that did not exhibit the issue.
-Ammo was NORMA 115gr. FMJ and hasn't shown to be at issue previously.

What is occurring is a failure to feed on the last round in the magazine. A tap, rack addresses the issue, feeds the round which then fires and locks the slide back as it should.

Any ideas off the top of anybody's head or just chalk it up to a bad mag and call it a day.

As always I am grateful for any knowledge passed on.

I’d disassemble the mag, make sure the spring is properly installed, give it a quick cleaning while it’s apart, and then reevaluate. If it still gives you issues, but the gun functions fine with all of your other mags, I’d do as you said and chalk it up to a bad mag. Maybe reach out to Glock to see about a replacement magazine.

Yeah I’m going to take the mag apart when I have a second but I hate taking Glock mags apart and I’ve never bought a Glock mag tool (like I should have by now)

You can pop it off with a glock tool or punch though thats not kind to the mag tabs. Its ok for a I dont usually do it though. Could the spring be getting old?

I run PSA mags in mine so I am unsure about the glock mags but even glocks very good springs do eventually wear.

quote:

Could the spring be getting old?

Brand new mag.

Take the floor plate off. Make sure the mag spring is assembled correctly.

Look for excess plastic mold flashing on the follower or mag body. Sometimes you have to take some off with an exacto razor knife.

Try hotter ammo. Perhaps the spring is really strong and not broken in yet and weak ammo doesn’t overcome the spring pressure.

Load the mag to ten rounds (full) and let it sit like that in the safe until you try that mag again. This will begin to break in the spring and initiate the initial spring set.

Label all your mags. Keep a spreadsheet with all your mags, how many rounds down range, any issues and any repairs or spring changes made.

Glock mags are cheap enough to just toss if they act up. Rare, but it happens.

Think I’ve figured it out. The follower rocks a bit as they all do but this one hangs up a bit and I think it’s going nose high and causing slide lock early. Probably just misassembled or like was said some flashing on the follower.

I broke down and ordered a Glock mag tool as I should have one and they are just a PITA to deal with otherwise.

Thanks all.