A5, I am looking at doing a 7/8 oz of #6 folded. I have some Kent upland in 6s and it has worked great all year for me. I also have some Boss in 4s and 5s, both are folded. I did use some Boss fives for the second shot late this season and they seem to work. Good news was I didn’t have to use the second shot very often. I will pattern the Boss ammo this summer and see how they pattern. I understand that there aren’t a lot of 4 pellets in a 28 so the pattern might not be there. If I need to I can learn to do a roll crimp, I have done some research on it. I usually hunt alone and with a gsp, so I don’t take many long shots, but still get my share of birds.