I took a 308 and a 8.6 blk both ar's to the range and was shooting the 308 when I reached for more ammo and all the sudden realized that one might camber in the other. The range officer said not to try there so went home and found not only will it camber but also will fire. I started with 308 dummy round no powder and the bullet stayed but the primer backed out only a fraction so I knew I was safe. I chambered the same in 8.6 with the same results. I did not need the surgeon general to tell me the results if they had powder in them. I now no longer take both to the range on the same trip and I red taped the 8.6 and yellow taped the 308 and the same with the ammo. I hope this is of help.