I'm getting ready to buy a new AR which most likely is going be a Colt 6920. But I see that they now offer the 6949 which is the same basic rifle but has a monolithic rail upper. Does this type of upper have any advantage over a standard flat-top upper other than ease of adding accessories? For that matter are there any disadvantages anyone can think of?

What is a monolithic upper versus a Picatinny upper?

I guess I could have asked that with more clarity. I'm talking about an AR upper with a monolithic Picatinny rail and quad rail system that are integral to the upper assembly. Like this one from LMT.
LMT Monolithic Upper

No real advantages or disadvantages other than it is all one piece so what you buy stays as is.

Perry

I can build the entire rifle for what that upper costs on its own. I really don't see the advantage in it. But if it's what you want, go for it...

Check out Armalite's web site for they are also offering one and give some reasons as to just why?? Claim more stability with mounted options, lights, lazer's, etc. Military is always prone to hang various items on their weapons, but see very little use for ordinary civilian application. If you would try to track the evolution of the 15/16 platform it would be a very lengthy project. That is not a bad thing, but am sure there are other innovations just around the corner. Believe it is the longest serving shoulder fired weapon in U.S. military history.

quote:

Originally posted by DavidReed:
I'm getting ready to buy a new AR which most likely is going be a Colt 6920. But I see that they now offer the 6949 which is the same basic rifle but has a monolithic rail upper. Does this type of upper have any advantage over a standard flat-top upper other than ease of adding accessories? For that matter are there any disadvantages anyone can think of?

Biggest advantages - you have a free float barrel no matter what you bolt to it and room to play Barbie AR with accessories.

Biggest disadvantages - rails are nothing but deadweight and sharp edges unless you plan on using a scope/NVG, a vert grip, a PEQ and a light.

You didn't mention what the rifle is for and that would be the biggest factor in determining the value for these advantages and diadvantages.