FX 600mm Barrel / 5oomm liner

U can probably get parts outer barrel from FX and probe and shroud from FX cheeper then buying a kit I bought a 500 shroud from FX 75 bucks some one was saying the outer tube for a 700 was like 58 bucks then just get a caliber change kit from Huma air I think there 99 backs or something like that that's the barrel nut and other side plus TP and probe i believe it would be a little cheaper doing it that way