The SCAR is much more like An FNC over the M16/M4 type!
Bascially the M16 and M4 as we know looks kool. very accurate and ergonomics is the best! but it has an inherit problem whereby the gas system having to blow back into the bolt carrier that create 1) access HEAT in Full auto firing 2) carbon built up! thus reliability suffers!
SCAR bascially eliminate that with a piston just like FAL or AK type action where by a piston rod push the carrier and action instead of dirty gas! and without that also reduces heat in the firing area and thus reliability increases! SO to answer most questions, the FNC type action will be much more reliable than M4! hands down!! erognomics may not be there..
Not saying M4 is not good just there are better system out there. I am a die hard M4 fan and recently got me my Ultimate M4 which is a piston base M4 !look at the post I have in this board! it has the ergo, accuracy and all the kool ninja stuff I can put on the M4 ... and also a piston to eliminate the fundamental problem of the M4,
DaveC!