State mag limits are not trumped by LEOSA. Since Glock explicitly teaches that reduced capacity mags should not be used for duty, I would not carry them for any serious purposes and in fact do not not own any. If I go someplace with silly capacity restrictions, I take other pistols/revolvers.

State ammo laws are trumped by LEOSA, but NJ continues to try to jam up the retirees and out of state cops. Remember that even if the officers you encounter are not as dumb as that A-H Sgt. at NJSP firearms (who has been quoted by real cops as saying that they do not care about the federal law and will enforce state law), the prosecutor is the one who makes a charging decision. You would eventually prevail, but it would be an expensive mess that would take a while to solve and during that time you would probably be a prohibited possessor under federal law. I would avoid going into NJ unless being paid one heck of a lot, and even then, I'd probably do without the money and just skip it.

__________________
NHI, 10-8.