Old thread, timeless topic.
Much more than just the gun when shooting 10 shot groups, even with a capable gun & capable ammo.
Concentration & technique become paramount. Mainting cheek weld & consistent sight picture is very hard over 10 shots with a gas gun, even with bags like the Bull's mentioned in previous comments.
Truly it takes a supberb effort to shoot 10 shot <MOA, consistently by most people.
As time has passed, I think shooting a series of 5x5's is a better assessment of the system (shooter, gun, ammo) than is 10 shots for MOST shooters. At least for me, & in MHO.
None of my "working" guns have PRS stocks nor do they have very heavy profile barrels, as they are intended for purposes other than bench competition, but the stock (& subsequent improvement in consistent cheek weld) & barrel weight/stiffness are big steps forward in group shooting.
And, I've come more to subscribe to what Jack Leuba is trying to relate in this old article.
Let's Talk About Accuracy
Also, here's a link to another long running thread about "regular" guys chasing the 10 shot / MOA Grail as well for your reading enjoyment.
Black Rifle Challenge
MM