Preface: I'm a centerfire shooter, shot 1K comp back in the 90's, reloader at heart. Basically, meaning, I'm not brand new plinking.

That said:

I recently bought a new MKII bull barrel. Bone stock other than a 20MOA EGW rail and an Athlon 5-24X50 scope and I put it in a Boyd At-One stock. After 200-300 rounds, the best group I can hold at 100yrds is 1.5" As a reloader, this is driving me nuts!!! And is totally unacceptable. However, I have no control over rimfire loads. So, I don't know if this is expected and acceptable. Granted, this IS acceptable for a squirrel gun. But, I want this to be a respected PRS style rimfire. My intention is to use it for "E"LR rimfire matches (out to say 350. Which, I have tested it at 300 and it maintains an 8". But that, too, was with a 3-ish L-R wind)

Oh yeah, ammo tried: Wolf match, Dynamint match and Eley Black box match. With each new brand, I ran 10-15 rounds thru, before checking group size. Best groups are from Wolf Match.

I basically would like like to know if I need to be satisfied(which probably ain't gonna happen) or go deeper into the rabbit hole!