KAS RAS won't clear Delta Ring on 6933
I am almost embarrassed to post this, since I have installed several Knights Rail Adapter Systems on both Colts and LMT carbines. Tonight I have been attempting to install as new RAS on my 6933 and I cannot get the top rail half to clear the delta ring. I have even used two different delta ring tools but the ring bottoms out without allowing the back end of the rail to slide on. This has never happened before and I am at a loss to figure this out. I've tried it horizontally to allow the rear RAS clamps to slide over the gas tube, but the delta ring does not retract far enough to seat the back end of the rail. I will add that the teeth of the barrel nut seem to be catching on the inside of the top rail at the back end and are gouging in the inside of the rail.
Any suggestions?