I think the OP has it backwards. I find the 1 oz load in the 28 ga to be inferior to the 3/4 oz. It has long been known that the longer the shot column and the shorter the crush section of the wad column the poorer the patterns tend to be. Large shot in comparison to bore diameter adds to this problem. I've gone down the rabbit hole of trying to get a given bore (28 included) to step up to a larger one and it tends to not work out.
If you read the beginning of my post, I mentioned having read the 3/4 have a better pattern.....than 1 oz........
I was asking IF the 3/4 loads were inferior compared to the 1oz, in the field, based on folks experience.
We were on the same mindset.......Better density is what I was referring to.......and it sounds like folks are doing great with loads LESS than 1 oz.
FWIW, I was pretty please trying a 7 1/2 load in 3/4oz, the Federal Top Gun at 1,330 on a few rabbits. One shot was around 35 yards as it ran into the woods after an opening. I had plenty brush but the 7.5s did the job well. I believe it was an improved modified tube.
Wondered when in thick brush, if an open choke at close range would be better with 6s to avoid 'peppering' with too much shot? Friend swears by his 1100 20G, using 1oz high brass 6s, with an improved cylinder and used effectively at 30-35 yds.
Thanks folks.