My personal defense trainer said that a 20 ga. with #3 buckshot was a good choice , I understand your point about over penetration , but as with the hand loaded cartridge , has it been a problem ? My aunt was in her house when a man shot at a deer in her field , a 00 buck pellet went about 60 yards , thru. the wall of her house and hit her in the leg , the wall was 90 year old pine , no insulation and 3/8 sheet rock , it bruised her leg . hollow point bullets are wonderful right up to the point that the cavity fills with cloth , leather , sheet rock or some other media the bullet passed thru. then it is a solid . i don't intend to get into a your guy / my guy fight , i don't know your teacher , mine spent time in the middle east ,South America and Centrial America teaching and working in VIP protection , in the US he trains police , body gaurds and private citizens how to stay alive in life threating situations . It comes down to how one wants to go about protecting themselves , i want the best chance of survival i can have ! Did your man tell ya to pick shooting lanes in your home or to get low and angle shots upward to minize the threat to others , check out whats going on in govt. buildings , the walls are being bullet proofed and relocated to provide safe shooting zones so they can repell terroist attack , they didn't switch to less effective ammo !
Its much like the .45 vs. 9mm debate if you get the chance to learn first hand and live your choice was good on the other hand your choice might get ya killed ! The 45/9mm debate was easy for me , every thing i read said this 9mm bullet will expand to .45 size , in my backward way of thinking i figure why not start out .45 and if i get expansion I'm better off !
One last consecration , when i load my gun for self defense how do i know when or where or if it will be needed ? sort of like a fire ext. do ya want a little one or a big one ? or spare tires , do ya like the one time use ones that go 45mph or a standard tire spare ?