FASCINATION ABOUT COLT 6940 VS 6920

 Actually, I wouldn't shoot one particular.  Time to move on to a whole new rifle.  Get an LMT or HK if you like military services fashion pistons.    Colt has no real interest in helping you out.  They abandoned that project prior to their last individual bankruptcy.Worn out rings. Tried Colt customer service. They say it is out in the a sin