You can kinda see the rib in the back,, they lock in just fine, I'll post a range report when I get a chance to shoot them.
Edit- they have no stamps or any markings that would suggest their origin.
Sgt. of Marines, 5th Award Expert Rifle, 237/250
Expert Pistol, 382/400. D Co, 4th CEB, Engineers UP!!
If you start a thread, be active in it. Don't leave us hanging.
OEF 2011 Sangin, Afg. Molon Labe