Custom barrel for a Tool Room (early prototype) S&W 76. Note that the rear face of the barrel nut
is NOT serrated for the nut latch usually found on 76s. Instead, the Tool Room guns used a leaf spring
which engaged the straight knurled serrations on the nut body. This system is very similar to that used
on the US M3 "Grease Gun". The 3/4-10 threads on the front of the unit fit the MAC 9mm suppresssor. This
barrel has the retaining nut permanently attached and installs & removes from the receiver as one piece.
The color difference between the nut and barrel is do to the nut having been heat treated which causes the
different shades of gray when Parkerizing.
NOTE: Threaded barrels DO NOT come with a thread protector. Thread protectors are available at extra cost.