I happen to own all 3 (Ruger GSR, M1A Scout and M1A SOCOM 16).
Of the 3, the Ruger is the lightest and most accurate.
Between the 2 M1A's, the Scout is the most accurate of those two. The Scout averages 2.5 inches at 100 yards with my handloads. The SOCOM is a 3.5-4 inch gun at the same distance.
Ballistically I find I lose very little between the the 16.5 inch barrels and the 18 inch.
People shouldn't believe what they read/hear about velocity in 16" 308/7.62X51.
I cant speak to velocity generated by factory loads but my Handloads of 45 grains of WC844T in LC brass with 165 grain BTSP bullets gives me an average of 2700 FPS in the Ruger and SOCOM 16. They will certainly reach to thr 800 yard mark with authority.
I will concede that the short barrels are loud but there are work arounds for that if your inclined to participate in the NFA process and purchase a suppressor.
Of three I own, two of mine are configured for suppressors.
They work extremely well and provide a recoil dampening effect (due to weight) as well.
Of the 3 the only one I have carried all day long is the SAI Scout. I have carried it hog hunting and have found it to be a little cumbersome/heavy. It would probably be ok if hunting from a Shooting House or Elevated Tripod but for all day carry in thick brush it was a bit of a pain.
I will admit that the suppressor compounded the Scouts issue with portability. Without out it it was a better but the rifle was sighted with it on so I left it in place for the hunt. It performed extremely well on the hunt and I expect that very few bolt gun operators could be as quick on follow up shots as someone with this platform and sighting system (Bushnell Holosight).
With respect to the Ruger, to date I've run about 600 rounds through it and will be carrying it on a late Spring Hog Hunt in TX.
I expect it to perform well.
Is it a battle rifle, I don't think so (although battles have been fought with similar platforms)
Is it a Scout rifle, I don't know.
What I do know is that Ruger GSR is a light handy 308 bolt gun with factory iron sights that has an excellent trigger.
It is extremely accurate and with handloaded ammo it's the ballistc equal to any 308 on the planet.