This is Kinda off topic..But

Can anyone tell me the what the law is regarding
A mag ext on my M1 super 90?

I was told that because it was a post ban gun that I cant put the 4 round ext on it?

Even with the 4 round ext it does not hold more that 10 rounds.

Thanks for any help

18 USC 921(a)(30(D) is the pertinent section.


(D) a semiautomatic shotgun that has at least [b]2[/b] of -

 (i) a folding or telescoping stock;
 (ii) a pistol grip that protrudes conspicuously beneath the action of the weapon;
 (iii) a fixed magazine capacity in excess of 5 rounds; and
 (iv) an ability to accept a detachable magazine.

The magazine extension is OK if you don't have a pistol grip.