I want to FF my Dissy and be able to use my A2 handguards. Which manufacter's tube should I go with? What about gas blocks. I'm guessing I may need a low profile gas block to fit underneath the float tube.

My stock BM barrel is turned down to the M4 profile. How do I make this float job look just like my CMP upper?

Thanks,

Gunzer

Easiest way would be to get a 20" barrel and cut it down to Dissy length, rework the gas port for reliable operation, if needed, and FF it using the DCM/CMP FF tube and A2 handguards.  I'm not aware of a gas block low profile enough to fit in the DCM/CMP tube.  Maybe you could modify the DCM/CMP tube - cut it out where the functional gas block is, but saying that and actually doing it appear to be two different things.