I like the Pac-Nor polygonal rifled barrels. They are exceptionally accurate, easy to clean and for me have given excellent service.
Pac-Nor 1:10" twist Remington Varmint Contour 24" Super-Match S.S. barrel with Vais muzzle brake, .308 Winchester, Remington 700 S.A. using Pac-Nor Rem-Nut barrel nut, 10 shots @ 100 yards, eight shots through upper hole:
Pac-Nor polygonal rifled 1:9" twist 24" Savage Varmint Contour Super-Match S.S. barrel, .223 Remington chamber, on Savage Precision Target Action. 10 Shots @ 100 yards:
Pac-Nor polygonal rifled 1:8.5" twist 24" Savage Varmint Contour Super-Match S.S. barrel, .204 Ruger, on Savage Precision Target Action, using Berger 50 grain HPBT bullet (now discontinued) that required a slightly faster 1:8" twist. 10 shots @ 100 yards:
The limiting factor seems to be my marksmanship, although in varmint calibers the ground squirrels have few complaints.