It's hard to compare barrel companies, prefits, and custom chambers/gunsmithing. So you'd have to compare apples to apples. Chambering / Gunsmithing to your action has a huge effect on the results. Then you can go and compare the barrels.
Speaking to Modacam, he found Kriegers to be the overall most consistent. Bartleins were up there, and then Benchmark would shoot really well, but would be pretty picky with ammo. Kriegers not being too picky. He has his own custom chamber.
Then you have DI Precision with their own chamber, and you have Vudoo with their own chamber.
Then you can pay for what you're chasing. Green Mountains when chambered well will do fine, but you aren't going to find any benchrest / f-class winner using one. Now in a PRS/NRL22 sport is a .3" vs a .2" going to make a difference? Probably not too much... so it just depends on what you're chasing.
Also the definition of what hammers is pretty subjective too. Is a .3" avg a hammer? For some that might be a bad day, and a .2" is a hammer. Friend with a RimX, went from a Proof, Keystone GM, Modacam Krieger, and every time it "hammers" smaller and smaller.
So first off, I'd choose a good renowned smith. Not some one who is like "send me a reamer, and I'll ream it for you" kind of smith, but someone who really knows their craft and has their own proven reamer (magic sauce). Then you can ask that smith what barrel they like.