may i ask what kind of load(s) your using for your AR? bullets, powder charge etc.
My best load is 22.4 gr of 8208-XBR pushing a 60gr Nosler Vamnint tip with a cannelure and a light roll crimp after bullet seating with the Redding seater die. I was able to get a sub MOA at 100 yards with my Colt and I'm very happy with it - picture below.
I thought I'd try finding the perfect load for my ML this fall as well - it's good now, I'd like it to be great . . .