CMMG 6.8 SPC II Uppers have the following standard features.

4140 chrome-moly vanadium steel barrel
6.8x43 SPC SPEC II chamber, since January 2008
1:11 twist
Four Groove Rifling.
Hard chrome lined chamber and bore
M4 feed ramps/Barrel Extension
11 degree recessed target crown
1/2x36 Threaded Muzzle
WASP Treated Barrel
F marked front sight base for flat top receivers
Round M4 Handguard cap
Each barrel is individually magnetic particle tested.
Barrels are engraved CMMG WASP 6.8 SPC II 1:11.