I have a McGowan SS bbl in 6x45 and its a tack driver. Its on my Savage FP10 action I built it for my 400 yard Antelope/coyote gun.
My 95g NBT load goes right at 2" at 400 yds.
It rarely has cooper buildup/fouling very easy to clean. When I got it I put my borescope in it and it was absolutly perfectly smooth with NO land/groove marks.
I would not hesitate to get another one from Jim at NSS.