I didn't have any trouble when I was selecting HD rounds and was trying out Winchester and Hornady LR rounds. OO Buck and slugs worked just fine. I will say that I couldn't float an extra round with the LR stuff though.
I know what you mean. when I first shot mine I tried out the low recoil versions and the full strength semi auto versions. The LR work just fine but the SA stuff was painful. Also, the shot patterns for the LR were tighter than the SA. I found that I prefer the low recoil buck and slugs and that is what I have in it for HD.
I shot Winchester Ranger low recoil slugs through my M4 just fine. I missed the bulls eye by only 3-4 inches at 100 yards. Granted I only shot the one shot at the target. I figured I didn't want to press mu luck any further. LOL
I tried it out along with some of the LE red box semi-auto and the LE low recoil stuff. I found that the two full strength, the semi auto red box and the FPD stuff, gave pretty crappy patterns. Only about 2-3 of the pellets were in the 12 inch circle. The rest was scattered all over the paper. Some 12 inches outside the circle. The low recoil onthe other hand had great patterns. That is what I'm using in my M4.
No. Well, as far as I know it won't. There is a fake tube extension that screws on the mag tube to make it a proper length. There are some people on here, like SOCOMguy, who makes a full length mag tube that you can buy that'll bring it up to 7+1.
I have to go with tucker. What if you only have time for one shot. I'd hate to be in a situation where I only had one shot to save my, or a family member's life, and only have a blank in the chamber.