Are these full-size or short-barreled? I would think that a sub-11” barrel and a 30 round mag would be great for personal defense.
11.5” is minimum. Below that, a lot of the power just gets turned into ear-splitting noise (on top of the fact that a normal-length AR15 is already very loud). Slap a suppressor on a sub-11” barrel and the back pressure becomes destructive; many top suppressor manufacturers will not warranty their cans on such short ARs.
That said, I do think an 11.5” barrel and a 30 round mag of 5.56 is ideal for home defense (to wit room-to-room CQB). Maximum penetration and stopping power balanced with good maneuverability, capacity and mitigated over-penetration.
“A personal defense weapon (PDW) is a compact semi-automatic or fully automatic firearm similar in most respects to a submachine gun, but firing a (often proprietary) rifle round, giving a PDW better range, accuracy and armor-penetrating capability than submachine guns, which fire pistol-caliber cartridges. The class of weapon as it exists today evolved as a hybrid between a submachine gun and a carbine, retaining the compact size and ammunition capacity of the former while adding the ammunition power, accuracy and penetration of the latter.”
Silly rabbits—mere citizens can’t be trusted with such nifty weapons: PDW’s!
Only hired hands of government alphabet-soup agencies that sound like something Orwell would dream up, if he reported to Heinrich Himmler circa 1940, are qualified to handle them.
(Naming contest, 2nd Place: Department of Fatherland Schutzstaffel)