Glock 21SF mags don't drop free

[jumbopanda]

I have a brand new G21SF with latest generation full metal lined magazines, and they just won't drop free. Is this a common problem?

EDIT: Actually, since Glock just came out with the Gen 4 mags, these would be one generation older.

[glocktogo]

I've had this problem with all my 21SF mags. I've shaved/trimmed/sanded them on all the high spots and now all but one of them drop free just fine. Nothing I do will make the one mag cleanly drop every time.

[jumbopanda]

Originally Posted by glocktogo

I've had this problem with all my 21SF mags. I've shaved/trimmed/sanded them on all the high spots and now all but one of them drop free just fine. Nothing I do will make the one mag cleanly drop every time.

I noticed that the inside of the frame slims down where the thumb dimples are. Would sanding those parts down be a good idea?

[eternal24k]

my Glock get hot and the thin area you are talking about sunk in, I was able to take a heat gun and push them out a little bit. I also sanded my older gen mags to drop free.

Is this a new or used Glock?

[jumbopanda]

Originally Posted by eternal24k

my Glock get hot and the thin area you are talking about sunk in, I was able to take a heat gun and push them out a little bit. I also sanded my older gen mags to drop free.

Is this a new or used Glock?

It's brand new. I would be kind of scared of using a heat gun because it's not very precise. Knowing my luck I'd probably end up warping the whole frame.

[glocktogo]

I think modding the mags is a safer bet unless you have some experience modding polymer frames. My mags stuck with the gun stock out of the box and after having the frame modded, they still did. I now have 5 mags that drop free every time and I reserve the one that doesn't for practice. It doesn't take much skill to mod the mags.

[Skintop911]

Hit the mags with a sharpie or grease pencil to find the high spots that are creating friction. Then, hit them with some fine sandpaper, remembering that material is easily removed, but not replaced.

That being said, I wouldn't ever be totally reliant upon a mag dropping free. Have a back-up plan.

[GLOCKMASTER]

Originally Posted by jumbopanda

I have a brand new G21SF with latest generation full metal lined magazines, and they just won't drop free. Is this a common problem?

EDIT: Actually, since Glock just came out with the Gen 4 mags, these would be one generation older.

Since it's new and if you purchased it from a gun store I would either take it back or call Glock.

[jumbopanda]

Well, I ended up spending about an hour and a half just sanding the thumb dimples on the inside of the grip with 150 grit sandpaper and all seven of my mags now drop free! I'll probably go grab some 220 and 400 grit to smooth it out when I have time, but as it stands, things seem to work fine.

[AngeredKabar]

Is this a pretty common problem for the 21SFs? I'd like one eventually but this makes me weary.

[jumbopanda]

Originally Posted by AngeredKabar

Is this a pretty common problem for the 21SFs? I'd like one eventually but this makes me weary.

I probably would have been weary of buying one too if I was aware of this issue before I bought it. But as it turns out, the fix was pretty easy and I'm very happy with the gun so far.

[misanthropist]

I have a 20SF (same frame) and this does not happen with mine.

[eternal24k]

My 21SF has no problems