Just found this tonight, thought I might share it with you guys. Forgive me if this is old news....
Extended USGI M7 Bayonet for 16 inch Barrels - with Factory New M10 Sheath
New production USGI M7 with extension for mounting on 16" barrels with bayonet lug.
These were custom built by the U.S. mfr of the M7 for DoD. Each knife has a welded extension (under the grips) that extends the length and allows use on 16" barrels for carbine AR's. The handle gap is filled by using an extra portion of handle that match the
existing full length handle. The latches are peened (permanently attached).
Extended USGI M7 Bayonet for 16 inch Barrels - with Factory New M10 Sheath
New production USGI M7 with extension for mounting on 16" barrels with bayonet lug.
These were custom built by the U.S. mfr of the M7 for DoD. Each knife has a welded extension (under the grips) that extends the length and allows use on 16" barrels for carbine AR's. The handle gap is filled by using an extra portion of handle that match the
existing full length handle. The latches are peened (permanently attached).

