I'm not trying to stir up a nest here, but I thought that because the 7600 mags also fit into the 7400 (semi), they were limited to 4 rounds. I hope I'm wrong, I would love to get a high capacity mag for my 7600.
My understanding is that they were not manufactured for the 7400 Semi and not marketed as fitting the semi, so there is no restriction. If there is a manufacturer out there that states on the packaging that the extended magazine fits 7600 and 7400 then it would be restricted to the legal limit.
I agree
If they are designed to work with the 7400 they're a no-go, but 7400's have a bolt release built into the mag. I haven't seen any of these aftermarket mags with the bolt release built in. It's a sliding button on the side of the mag.
Not necessarily. The design is not the issue but the intent of the manufacture. LAR mags fit the AR pistol and are restricted to 10 rounds but by design will fit in the AR rifle, whose mag capacity,as we all know, is restricted to 5 rounds. The intent of their manufacture was for the pistol not the rifle and they are not marketed for the rifle. It is just a "coincidence" that they fit.
The Colyer mag, IIRC, did not have a bolt release for the 740 and 742 rifles.



























