Glock 20 Feedlip Gauge

[DenStinett]

A year or so ago, I was looking for some info on the Specs of the Feedlips for the G-20 Magazines
I found this info on Glock Magazines:
http://10mm-firearms.com/general-discussion/g-20-mag-issues/msg80720/#msg80720

I noticed that the Max Feedlip spacing for the Glock 20 Mag was 0.378"
For some reason, and I wasn't sure WHY, but that number struck me
Then it dawned on me .... It's the Min Case width of the .357 Mag

Today I took a Sized, 357 Nickel Case and mic'ed
Sure enough, 0.378"
So I thought; "maybe that could be helpful"
I took my handy-dandy Safety File and a couple Number Punches and made this:





I filed two spots, 120^o off each other, and left the third spot untouched
This gave me three set measurements across the Case:
0.370, 0.374 and 0.378
Now I can take my little Tool and quickly check the Feedlip Spacing on my Glock 20 Mags
I checked the two new G-20 (15 round) Mag with the Gauge and they are a snug 0.370"
And as it turned-out, the Feedlips on the 20 Round, MG20 Mags were well over the .378 Max
Now I've set them back to 0.370" (same as the Factory Mags) and we'll have to see how that works-out

[The_Shadow]

Good info!  I have seen where some mag lips were spread out especially near the front edge.  I think that had led to some peoples issues, as ammo nose dived or stuck to the left of the feed ramp...
It is something to inspect should feeding issues appear!