I changed my first barrel on my axis . Its a 7mm rem mag. got the bolt head from pacific tool and gage. the bolt head is their stock SHORT ACTION magnum . it required no machining and the firing pin protrusion was perfect. the ejector and the extractor worked perfect . since it was my first barrel change i bought a cheap used barrel. it was like under 30 bucks on ebay . i figured if i screwed it up so what . Also i wasn't sure i would like recoil from a large magnum . it went in a axis plastic stock . The gun was light . recoil was not too bad . The axis recoil pads are nice . i shot stock hornady ammo . it grouped terribly lol. i figured that it would . NO ONE SELLS USED BARRELS THAT SHOOT GREAT. my belief at least . the barrel came off easier than i thought. i used oak block in a bench vise . i took the wrapping off an aluminum baseball bat . wrapped it around barrel cranked up vice real tight and gave barrel wrench stout tap with breaker bar and whala it broke nice. screwed in barrel against foster go gage . checked bolt operation. then checked no go gage and non bolt operation . i was off to range . shot well fed well extracted well and ejected well . could not be happier. now to buy real barrel and possibly others . thanks for reading and know magnum axis dose not have to be difficult. excuse my typing but u get point.