There seems to be a bit of a pistol caliber carbine craze going on right now. But nearly all defensive 9mm ammo seems designed around 4" barrels, and the rest for shorter barrels. Is there anything out there that is optimized for carbine length barrels (assuming 16") or long barreled pistols (NFA length weapons, whether actual SBRs or braced pistols)? I think there'd be a market for such.