7.62 x 51mm / .308 FMJ no headstamp ID needed

I have a 7.62 x 51mm or .308 Win magnetic FMJ with no headstamp that could use some ID. The rim is beveled a bit and there appeared to be shoulder annealing. Does not have visual signs of reloading but has an odd circular primer crimp on nickle primer. Someone wrote boxer primed on the round?