Think this barrel is going to be a keeper. Was cold out today , not best condition for co2 gun. But was eager to see how this new barrel was going to do. Was using dot sight, think scope and warmer weather will shrink these groups. I got the barrel from Henry @ http://www.crosman600repair.com/services . I know one thing, I am not wasting anymore money on Crosman barrels for these 600s. All groups were at 30 feet, some 5 shot and some 10 shot. Best group 10 shots bottom row right of sight in target.