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I haven't done it before, but they are made to the same specs, use the same gas rings, etc. Even using different bolt/barrel manufacturers is OK unless there is something wrong with the parts.
The only possible exception might be Colt. I don't think they changed specs that would matter in your case, but they changed things around so much that you never know - or at least I don't [:)]
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No, Colt hasn't changed any of the bolt/carrier dimensions[:D].
Re the carrier cutaway areas I'm in total agreement w/SFC. The closer you can get that assembly to the weight of an M16 setup, the more reliable function and less wear you'll get over time.
All my ARs have GI carriers with the sear trip shoulder cut back. Started doing that back in 1978, and have seen no reason to stop it[:D]
Acquired a new DPMS lower a few weeks back, and it came with an unnotched hammer, which tells me that they've stopped the cutaway under the firing pin also.