I trick out my youth 870 / 21 in barrel with Trulock 565 non-ported for a good all around choke and the surshot stock.. i like the 21 in. barrel better because it will cut down on the recoil just a little more than the 18 in barrel. Your going to want to change out the stock anyway after a little time using one..Also with the 21 in. barrel after screw in choke your going to gain another inch or so...I top mine off with a simmons pro diamond scope in low power..