You need to install a m2mag catch as mentioned. 30rd mags have a couple of dimples on the rear which is supported by a L on this catch. Earlier models on the mag catch don't have that l.
I would not buy aftermarket 30 rounds mags poor reliability.
The military ones are getting or have got pricey but they are around.
Do a google search for military m1 carbine 30round mags and you can find the original manufacturers.
Quite a few companies made the 15rounders and some of them are quite collectible.
and yes, i have seen 30 rounders fall out of the bottom of some carbines.
They are a neat little toy especially with the m2 registered go fast switch.
Last edited by RoninPhx; 11/20/15.
