18" Liberty COAL finally measured

[45r]

Sounds like your GTG.
Mine came about 30 to 40 thou shorter but seems to getting better with shooting and lots of cleaning.
It shoots good.
I might have to go to a lighter buffer with my CFE and 123 SST load..
It's a little weak cycling but is accurate.
My 85 grain sierra's shoot real good.
Your barrel should be pretty good with a near perfect length throat.