I have learned by reading threads here on this board that some brands of telestocks are manufactured with milspec buffer tubes and some are not.    This got me wondering about the rifle I bought from Bushmaster which came with an A2 stock.  Is there a chance the buffer tube on my particular rifle is not milspec?  Are non-milspec buffer tubes used on some A2 stocks like they are on some telestocks?  

Quoted: Is there a chance the buffer tube on my particular rifle is not milspec?  Are non-milspec buffer tubes used on some A2 stocks like they are on some telestocks?

Some companies use non-spec tubes.  But all the fixed stock receiver extensions (they are not 'buffer-tubs') are the same dimensions.  The differences are how they were made (forged/machined from stock, or cast) and if they have the required dry film lube inside.

Several companies use the 'commercial' receiver extensions that do not have the dry film, these also seem to be the most common amoung the parts suppliers.  I've used one for a build it worked fine, I've never had an issue with it - then again I've never really pushed that rifle/lower to it's limits.

All the Bushmaster's I've purchased use the 'military' type with the internal dry film lube.

Forest, thanks for answering my question and for correcting my nomenclature error.

Bushmaster rifle receiver extensions/buffer tubes use to be one piece.  A real nice part.  I use to buy those and put them on my Colt's rifles that had two piece tubes (Colt's has made them both ways).  Last one I ordered from Bushmaster was a real crappy looking two piece weld job, have not ordered another since.