I owned an M1A 'Loaded' rifle, and I liked it a lot. It shot as well or better than my AR15 Colt Match Target rifle, but I later learned that the Colt wasn't the rifle I was expecting it to be (and neither was I the shooter I had expected myself to be).
Both were divested, and I got to try the AR project again. But the second time, I started out with a Stag Model 6 Super Varminter with a 24", 1:8" heavy barrel. Big, big difference.
As much as I like the M1A platform, It was a chore to get well under 2MOA of accuracy out of it, and to keep that accuracy. This is said despite my undying love affair with the M14 I carried for over a year In 'Nam. I think it's an outstanding MBR, but I can also fill that need with my DCM Garand. Having the Garand, I got the M1A out of my system surprisingly easily.
With the Stag 6, moderately good optics and effective load development is about all it takes to get surprisingly good accuracy, and it's also a lot less likely to go away. It also makes mediocre ammo perform to a higher degree of accuracy.
I have added a CMMG 16 Bull WASP upper, to determine if a minimum legal length bull barrel on an AR will perform well, and may, with luck, find out later this week.
Greg