hi john when it comes to chokes i do change mine in my o/u for clays but i use a semi-auto for everything else and thats a 1/2 choke .but my gun for clays shoots high as it is a sporter and throw the pattern high, most sporter do but my auto throws the pattern flat,so its 1/2 below the bead and 1/2 above where the o/u is 1/4 blow the bead and 3/4 above, but that down to gun fit.i would'nt worry to much about choke or pattern. i change the size of the shot before the choke to suite what i am shooting at .knowing where the pattern is all u need to know,then it down to the man behind it.
che