I have no gauge pins this small to measure the flash holes in these cases (.308's). Then today I had a thought and got my sets of drill bits out to see if I could get some idea how large they are. So using my caliper on the drill bits, a .111" (2.82mm) bit into the flash hole with just a little bit of play (meaning, a hair larger). It's not exact, but it certainly gives you an idea how big they are and compare that to a typical large rifle primer flash hole that's at .080".How big are the primer holes. The 308s have a flash hole big enough to toss a small animal through. Visibly bigger that 0.1 inches. No pin gages in that size to check real dimensions.









