Oh those pesky buffer tubes.
I have been wondering how bad the "gassing" around the charging handle is from the .300 blackout when used with a suppressor.
I watched a friend test fire his M4-2000 on his 10" 5.56 Noveske. The gas leak around the handle (no it isn't a gas-buster, he has ordered one) seemed pretty bad.
"9mm has a very long history of being a pointy little bullet moving quickly" --Sevens