?? Not sure what is understood?? in your comments. You are saying the larger the barrel diameter the better the pattern period and no choke the best pattern
This is what you are saying and that is NOT the case with the 3/4 oz . In fact your comment all else being equal would be the same choke also would it not
Your post
I think it's a generally accepted concept that the same size shot, in the same amount, accelerated at the same rate to the same speed, will pattern better out of a larger diameter barrel. ie 1 oz out of a 12 gauge will pattern better than 1 oz out of a 20, all else being equal. The inference is that the less dense mass of shot/interference from barrel walls, the better the pattern.
Don't assume anything shoot some paper with them all and let us know what you see
What I have seen in 3/4oz, is the 28ga patterns better than the 12ga . I firmly believe the shot stack height of the 28ga gives it a tighter pattern and a longer shot string