Have shot 4mm the last two yrs. hunting and testing. # of shells shot 30--40
Out of a 590 extended choke tube, rated for steel. Mostly with a 1 1/4 oz load. THE CHOKE SHOWS SIGNS OF SWELLING !!!! I can get it out by hand still, but has marks on the sides where it is rubbing. Have also been shooting a mixture of the smaller shot also tss #8, 4, testing, and rem. hd #6 1 1/8 at a few ducks.