Purchased new 10 round mag for G21 (3d gen, I believe, since it has rails) from on line retailer.  Glock brand mag. received today.  Slides right in, but won't lock in place.  So apparently it's not the right mag, but why?  And anyone have any ideas how I could identify the right mag so I don't make the same mistake again?  Thanks in advance.  

31 minutes ago, jokerman said:

Purchased new 10 round mag for G21 (3d gen, I believe, since it has rails) from on line retailer.  Glock brand mag. received today.  Slides right in, but won't lock in place.  So apparently it's not the right mag, but why?  And anyone have any ideas how I could identify the right mag so I don't make the same mistake again?  Thanks in advance.  

Is it the same length as your other mag(s)

Yes it is.  

Ck the cut out for the mag release 

Are you attempting to insert the mag loaded to 10 and it isn’t seating? Or is this an empty mag.

Do you have a magwell on the gun?

I have tried to insert it both empty and with as many as 9 rounds in it--the spring is still too tight to allow the 10th round.  Nothing seems to permit me to seat the magazine so that it locks in place.  Have tried to do so both gently and with significant force.  Color me puzzled.  

Match up the cut out(s) on the new magazine to a magazine that works. See if line up. Post up some pics.

Are you using any aftermarket parts on your Glock G21, like a slide or magazine release? Does your G21 have all factory stock parts?

*Remove the slide from the frame and insert the empty mag. Does it still not seat the magazine?

*Try swapping the base plate/pad with another working magazine and see it that works.

Regards,

TokenEntry

Thanks to all for the suggestions.  I will give them a go.  

3 hours ago, Zeke said:

Ck the cut out for the mag release 

 

 

 

Are you sure they are for then Gen 3? I have a gen 4 G21 and when I ordered my 10 rounders I almost mistakenly ordered gen 3 mags. Not sure if it would make a difference but they did ask for which gen pistol the mags were for. They are Glock factory and I have 50 rounds through each with no probs so far. If you have the grip vent plugged maybe that's causing an issue? Good luck.....hope it works out!

3 minutes ago, vladtepes said:

 

 

 

We smert 

@High Exposure gonna be proud 

Was also thinking the Gen 3 vs Gen 4... but iirc the Gen 3 will work in Gen 4 unless you swapped the mag release to the other side...

@jokerman  Does the mag lock in place on an open slide locked back?  

2 minutes ago, vladtepes said:

 

 

 

That's what I was thinking! 

1 minute ago, Maksim said:

Was also thinking the Gen 3 vs Gen 4... but iirc the Gen 3 will work in Gen 4 unless you swapped the mag release to the other side...

@jokerman  Does the mag lock in place on an open slide locked back?  

That’s gonna be tuff for the lockback to pick up the follower if the mag falls out...

2 minutes ago, Maksim said:

Was also thinking the Gen 3 vs Gen 4... but iirc the Gen 3 will work in Gen 4 unless you swapped the mag release to the other side...

@jokerman  Does the mag lock in place on an open slide locked back?  

But will a gen 4 work in a gen 3? 

1 minute ago, Zeke said:

That’s gonna be tuff for the lockback to pick up the follower if the mag falls out...

Heh?

Take gun without mag, lock slide back.

Put mag in the gun.  Does it seat?  If yes, you know issue with the mag lips, etc.  If not, then something with the mag itself such as the mag release cutouts.

Just now, Moose11872 said:

But will a gen 4 work in a gen 3? 

Fairly positives... let me go check... 

Yes... with mag releases on the same side, Gen 3 and 4 mags on my Glock 22s are interchangeable.

4 minutes ago, Maksim said:

Heh?

Take gun without mag, lock slide back.

Put mag in the gun.  Does it seat?  If yes, you know issue with the mag lips, etc.  If not, then something with the mag itself such as the mag release cutouts.

Fairly positives... let me go check... 

Hold on empty. You’re thinking something else.

Did the firearm function properly with old mags 

2 minutes ago, Maksim said:

Yes... with mag releases on the same side, Gen 3 and 4 mags on my Glock 22s are interchangeable.

yes, on my Gen 3 and 4 mags, with the release on the same side, the mags are interchangeable.

@jokerman which side is mag release on?

17 hours ago, jokerman said:

Purchased new 10 round mag for G21 (3d gen, I believe, since it has rails) from on line retailer.  Glock brand mag. received today.  Slides right in, but won't lock in place.  So apparently it's not the right mag, but why?  And anyone have any ideas how I could identify the right mag so I don't make the same mistake again?  Thanks in advance.  

Wait a second, is this the ambi mag release G21 with the 1913 rail on it?

1 hour ago, diamondd817 said:

Wait a second, is this the ambi mag release G21 with the 1913 rail on it?

Yes, I believe it is.  

 

I have already packed up he mag to mail back for a refund...no more on line purchases for me.  Can anyone suggest a dealer south of, say, New Brunswick where I might try before I buy?

 

Thank you everyone.  

59 minutes ago, jokerman said:

Yes, I believe it is.  

 

I have already packed up he mag to mail back for a refund...no more on line purchases for me.  Can anyone suggest a dealer south of, say, New Brunswick where I might try before I buy?

 

Thank you everyone.  

That particular G21 model is known to have mag release issues. Glock has a "silent like" recall on them. Glock will replace that frame for free if you call them. I had one and the mag release fell apart. Frame was replaced by Glock. There is probably nothing wrong with that magazine.

 

Edit: Now I remember what would happen with this model. If I had a fully loaded mag inserted and then released the mag while it was still loaded it would cause the mag release to get hung up/stuck. If your mag release is stuck to one side, then yeah, the magazine won't lock in.

Thanks dd817!!

11 hours ago, diamondd817 said:

That particular G21 model is known to have mag release issues. Glock has a "silent like" recall on them. Glock will replace that frame for free if you call them. I had one and the mag release fell apart. Frame was replaced by Glock. There is probably nothing wrong with that magazine.

 

Edit: Now I remember what would happen with this model. If I had a fully loaded mag inserted and then released the mag while it was still loaded it would cause the mag release to get hung up/stuck. If your mag release is stuck to one side, then yeah, the magazine won't lock in.

Hmmmmm question.........

If it's sticks as you think should it not react the same way with the orginal mags? Once it's stuck it won't care which mag is in place correct? 

10 hours ago, My1stGlock said:

Hmmmmm question.........

If it's sticks as you think should it not react the same way with the orginal mags? Once it's stuck it won't care which mag is in place correct? 

Yes, true. Buts its unclear from the postings whether or not if a known working magazine was tried after the new non working mag was tried. I'm just posting my experience with that particular model which is known to have mag release issues. If it is in fact the G21 with the ambi mag release/1913 rail I am going to say it's a 99% chance it's the pistol. It could have been bought used from someone who altered the mag release in an attempt to make it work better and in the process they made it not able to work with say gen 3 mags. Lots of possible variables here. Pics of pistol and mags and more details would be needed to get the correct answer. 

Glock perfection

9 hours ago, Ray Ray said:

Glock perfection

No Glocks in yer inventory I assume?  Gotta have one at leasst Ray Ray! Don't say it is so! 

1 hour ago, My1stGlock said:

No Glocks in yer inventory I assume?  Gotta have one at leasst Ray Ray! Don't say it is so! 

You know what happens when you assume?  You make an ass out of u and me.