Originally Posted by
map55b
I checked with GMB this morning for clarification on their markings. Here is what they said: "In the last 2 years the RX, RXS, BX, and the BXS are stamped on the button exit end (muzzle) of the barrels. The gunsmith edition blanks if they have both ends are stamped the end with the “M” would be the button exit end (muzzle). If the gunsmith edition barrel has only one end marked it would be the breech end. Going forward the barrels are now going to be stamped on the button exit end (muzzle) of the barrel with a “M”."