This is probably a stupid question but being that I plan on buying an AR in the next year I've been curious about something... why is it that some ARs have a delta ring and some dont (sorry if this is the wrong terminology, im referring to the round piece that separates the hand guard from the receiver)? Why is it that some of the flat tops have that space due to the ring and others are solid all the way through? If you buy one with a delta ring can it be converted to flat top all the way across?

I am no expert but this is what I think is the situation..

 

there are a couple general setups

 

Delta rings and those flush free flat tube setups..

the delta rings slide back and allows you the ability to remove the hand guard, where as the free float tube I believe unscrews.. you can replace the hand guard with something like a rail section, or even just a plain free float tube as is seen on many ARs.. but generally speaking the delta ring is what holds the hand guard in place... on my old AR I slid the delta ring back popped off the existing hand guard and added a daniel defense railed hand guard...

A rifle having a delta ring and/or barrel nut is dependent on the rail system it uses.

An AR-variant, by default, will have a delta ring/barrel nut. However, some rail systems (which are for the most part free-float systems), like the Daniel Defense Lite or Larue rails (among many others) use their own proprietary delta ring/barrel nut that discards the default setup.

The only free-float system I know of that does not require removal of the delta ring and barrel nut is the Daniel Defense Omega series, which does create a "running" top rail.

Other rifles use monolithic uppers, which is a one-piece upper-- and in this case, use their own system within to switch out barrels, etc.

A rifle having a delta ring and/or barrel nut is dependent on the rail system it uses.

An AR-variant, by default, will have a delta ring/barrel nut. However, some rail systems (which are for the most part free-float systems), like the Daniel Defense Lite or Larue rails (among many others) use their own proprietary delta ring/barrel nut that discards the default setup.

The only free-float system I know of that does not require removal of the delta ring and barrel nut is the Daniel Defense Omega series, which does create a "running" top rail.

Other rifles use monolithic uppers, which is a one-piece upper-- and in this case, use their own system within to switch out barrels, etc.

 

 

the Omega is exactly what I had on my AR.. it was a pretty nice piece, and installation was cake.