u dont see me recommending a 308
EITHER Rich. The 223 is quite bad also. That's why a lot of Swat entry guys used CANNED 223's, or else use electronic ear muffs. The average guy should just use a 9mm Marlin carbinek, $300 used, not a shotgun, with Cor Bon's 100 gr powrball ammo in it (1600 fps, 550 ft lbs. The electronic muffs cost $150+, $250 in "sterio", so that you can hear where a sound CAME FROM. You also have to take the time to turn them "on" risk having low batteries, etc. A small, lw 223, short barrel, with a small lw "can" on it, and you are WAY ahead of the shotgun.
Basically, tho, you won't GET to any longarm in time, short of a riot or shtf. So a real pistol, real loads, and real abillity with it, plus real hand to hand skills, and body armor,are by far the most realistic answer to the "home defense' problem. Just WEAR the pistol. If it's too big and heavy to SLEEP while wearing, it's not a good choice, at all.