If you stay within the same cartridge family, caliber changes are simply a matter of swapping out barrels, however If you change between cartridge families - for example from a standard caliber to a magnum - you'll need a spare bolt head, due to the different case head diameters involved. Fortunately, our bolt heads are made to the same exacting standards as our barrels, so changing them out is simple and painless. Request to Purchase below.