HI fellas , just want to confirm in NJ A semi auto shotgun can have a mag capacity of 6 rounds, correct? i have a benelli m4 looking add extended mag capacity. Thanks in adavance.

following

Correct.  6 rounds in the tube (+1 in chamber).

Don't forget the "ghost load" 

HAHAHA. SO it looks like the extended mag tube for the benelli is out, That would put me at 7 Unless a smith can block it back to 6. Probably not worth the hassle.

Ah - The M4 already has a 5 round tube - I don't see any +1 extensions for it.

1 hour ago, Krdshrk said:

Ah - The M4 already has a 5 round tube - I don't see any +1 extensions for it.

Yes me either

Is there a mag capacity exclusion for dedicated competition firearms?

3 minutes ago, 70gto said:

Is there a mag capacity exclusion for dedicated competition firearms?

How long have you been in the Glorious Peoples Republik of New Jerseystan????

There's no exclusions for anything, unless you have a badge or a friend in high places.

Yup wishful thinking. I hear ya