AR-10 Upper/Barrel Interchangability Question

[Anthony]

Hello Everyone,

I have a custom AR-10 built on an Armalite receiver with a 20-inch Kreiger barrel. While this combination is sinfully accurate, I would sometimes like to have a lighter package for use in 3-gun competition, etc.

How interchangable are the various uppers built by DPMS and Armalite?

For instances, could I purchase an upper from DPMS and drop it into my Armalite receiver and have a reliable rifle?

Or perhaps use a DPMS barrel in a custom built upper utilizing an Armalite upper receiver?

Thanks for the input.