Hello all from a newbie to the forum. Am in the process of building a Crosman 600 carbine and am having difficulty finding a reputable source for an extended barrel. Have reached out to one shop in South Carolina and one in California without luck. I'm looking for a standard 24" long 7/16" Crosman barrel in .22 cal. machined to fit the 600, nothing exotic. Any ideas would be appreciated. Will post photos and performance improvements when the project is finished.