Just dont expect really good accuracy from dpms barrels. Their upper reciver is decent, ive got their a1 upper but i sourced the parts for it elsewhere. Dpms parts are metal injection molded and ive had forward assist break bolt hold open break and dust cover pin break.
If you go that route get the barrel and stripped upper and everything else from someone else.
1:9 will shoot 55 and 62 grain just fine but it may prefer one over the other accuracy wise.
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