Thanks for the info,
and will add this info,
I just received an email from Green Mtn bbl's,
per info received from them,
"They don't make any AR bbl's, only 22 LR Rimfire bbls".
and from little I know about AR's, I believe AR bore diameter is around .217"?,
the 22 RF bbl's would be too large of a bore diameter, ie, .222" diameter
to work properly for accuracy or fit the AR pellets etc.
If I am out in left field, let me know.