Ok I take it you want a 5.56/223 but but you really didn't say what you want. Berrel lenth on the bushmaster makes it more of a long range accurate rifle so that's what your paying for. While the DPMS is probably a 16' which is a short range.... really to an extent its apples and oranges.... and it all depends on the application you want it for. If you want to shoot the zombies eyes out at 300+ yards than you want a long range long barrel weapon but if you want to take them at 100 yards or less a 16' is plenty.
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