Problem solved: AGP mags feed birdshot but not buckshot - Why?

[jlbraun 0]

Problem:

AGP mags feed birdshot fine, but buckshot shells seem to bind and not be pushed up out of the mag quickly enough, or not at all.

 

Examination:

Some buckshot has a higher brass base, which binds at a very specific point in the magazine. See attached photos. The yellow arrow shows the location high brass base shells like 3" buckshot bind.

 

Solution:

Remove feed lips. Hold follower down with thumb. Take medium grit sandpaper and with moderate pressure take 40 swipes on each side at the yellow arrow to remove all mold flash, burrs, and take about 15 thousandths off. Take 600 grit paper and do another 40 swipes to smooth it out. Put feed lips back on. Done.

[BUFF_dragon 3]

great deal.... i'll have to try and see if that fixes the issues with my 'sticky' mags

Edited April 5, 2008 by BUFF_dragon

[hobbyshooter 59]

Gen 2 mags are molded with more clearance up at the top for just this reason. I ended up with too much clearance in mine and the 2-3/4" birdshot would pop forward out of the guide.

[THE_HUNTER 2]

I checked my Gen1 mags and see when I push down it can catch with S&B buckshot, though never in shooting did I ever have a problem.I little bit of sanding and they are better!Thanks for the tip!

[Ronswin 26]

I have the 1st Gen and had to take a file to that same area on my AGP mags and they all work great now. I recently had to do the same to Mick Porno's mags as he had the same issues. Before a major match, test all loads that you will be using as I found out the hard way that European high brass and American high brass shells have slight tolerance differences in those areas.

[uzitiger 193]

I used a fired Russian 12ga steel shell casing and hand cycled the magazine until the binding went away at the same area.

[gtnichols 51]

Oh Yeah I thought something funny was happening there!

Great work!