I’ve been playing with the 2 different 180gr hyTek coated bullets from Missouri using 2400 ang H110 in my 8 3/8” mod 686 and getting pretty much the same results. I can squeeze a little more velocity with the H110 but the 2400 is more accurate. I get around 1250fps with 12gr of 2400 and is the most accurate of everything I’ve tried with 189gr bullet. Got some of the 175 and 190gr from GT loaded up but hot weather has kept me from trying them