Mbamber

Looking to purchase a sight for benelli m4, I'm looking on cabelas, im leaning towards a trijicon, I want someone light, and small, send me some links please, but I'm not sure what fits, and whatnot Thanks in advance.

Just purchased a M4 tatical, im new to owning a semi auto, I have a 590 mossberg and from what I remember you can put anything in there and it will shoot, but that's a pump and I had questions about the ammo, I was told to use (High Brass) rounds and buy 1600 fps velocity rounds for instance they sold me Hornady Black, 12 Gauge, 2 3/4" Shell, 00 Buckshot, 10 Rounds, are these the only rounds this gun can shoot or is recommended to shoot, or is this just like the break in period, I want to purchase 00 buck but I dont know what to get and nothing I seen states high brass and all the other rounds I seen are about 1325 fps velocity