I had a SA Scout and did a lot of research on gaining the best accuracy for that rifle. I took the approach that I wasn't going to spend 1k on a rifle that I got for $1700 to begin with BNIB, to get it down to 1.5" groups. That quickly went out the window as I chased accuracy. I started with a NM trigger job from Sadlak. Next was the Bassett LOW scope mount, Vortex precision LOW rings, Vortex PST 4-16x50. Then unitized gas system by SEI, as well as a SOCOM gas plug, TI piston, SEI GLFS, gas system shims, shock buff, and SEI Op Rod. I also threw away the synthetic stock and went with oversized walnut stock and bedded the action.
Add all that up and Im right there at the 1k mark, with sales, shipping, taxes where applicable and time. It was a great project and I learned a lot. I love that rifle and ultimately the groups would hover around 1.5" and better when I did my part behind the trigger. Of course there are tons of different options, JAE, SAGE EBR, Macmillan stocks to help to shrink your groups, but those add weight to an already heavy rifle platform. The 1 thing about those stocks is the cheek weld set up is repeatable and consistent for your rifle when you scope it as you stated in your 1st post.
As FrankGreen said the GLFS and piston need to be in the same place to reduce as many variables as possible. I know I am on a rant, but take your time in researching the options for the platform and use the experience of the guys that have shot these guns for many many years as your guide. I learned a lot on The Firing Line forum. I also made a couple calls to the man himself Ron Smith and he helped me tremendously. PM me if you have some questions or if I was unclear on something.
I ended up selling the Scout because I just couldn't shoot it after 50 rounds. I know I know, but after 4 total shoulder reconstructions and 16 screws in there the recoil impulse had me flinching before I pulled the trigger. So I sold it to someone who loves the rifle, but still get conjugal visits with her
