I just use regular 7.62x54 cases , neck size them with a 6.5mm die until the bolt will close on them . I have 3 of the 6.5mm 71's and all work fine with ammo made that way . Since they are being loaded with a light smokeless charge , they fire form good on the first firing and are neck sized only after that . If you have a weak firing pin hit , you can help that by using pistol primers . They go off easier and are fine for light loads .