Hey guys I have a question. It was stated earlier in this thread to use a GI M2 ball round, not a commercially made one. I do not have or have ever had a surplus GI M2 Ball round, but I do have plenty of PPU 30-06 specifically for M1icon Garand.are the PPU dimensions exactly the same as the GI M2 ball round or is it just the commercial stuff that you can't use to estimate muzzle wear? I know PPU is obviously commercial,but would it be close enough for me to estimate my muzzle wear on my Winchester carbine?