[Jeff]

Anyone know of a reliable extension for USGI mags?

Anyone used this one from Ace?
ACE Mag Extension 5-Round Fits Standard AR-15 30-Round Mags Polymer

 

[Cossey]

If I recall correctly, adding one to say, a pre-ban mag constitutes manufacturing a magazine and would be considered "post-ban".

 

[Jeff]

If I recall correctly, adding one to say, a pre-ban mag constitutes manufacturing a magazine and would be considered "post-ban".

You can add extensions to a pre-ban mag. The only time you're manufacturing a magazine is if you make one from scratch or use a preban and alter it so that it no longer works in the firearm it was intended to be used in but works in a different gun.

 

[Dieter122]

Jeff is correct.

Its not manufacturing a magazine unless you alter it to no longer work in the original firearm it was designed for.

These are perfectly legal to install on any preban AR mag. Just as installing a grip extension + baseplate on a preban Glock mag.

 

[bpipe95]

Interesting. I wonder how durable they are.

 

[Jeff]

For $5 I might try a couple.

 

[dsdmmat]

For $5 I might try a couple.

my concern would be the spring hanging up on the magazine body's floorplate tabs. Unlike most pistol mags which have the floor keeper on the outer edge of the mag, the M-16 Mag's inward tabs may catch the springs.

 

[Cossey]

You can add extensions to a pre-ban mag. The only time you're manufacturing a magazine is if you make one from scratch or use a preban and alter it so that it no longer works in the firearm it was intended to be used in but works in a different gun.

Thank you for clarifying. I just remember a thread on here where someone seemed knowledgeable on the subject.

 

[Jeff]

Thank you for clarifying. I just remember a thread on here where someone seemed knowledgeable on the subject.

There is an ATF letter stating what the federal level considers manufacturing a magazine and it's basically what I posted above.

 

[Jeff]

my concern would be the spring hanging up on the magazine body's floorplate tabs. Unlike most pistol mags which have the floor keeper on the outer edge of the mag, the M-16 Mag's inward tabs may catch the springs.

Good thought. I haven't considered that. I wonder if the extension puts some sort of ramp or guide near the tabs to guide the spring around them.

I guess I would also have to go with a +5 or +10% spring too.