The BCA Kodiak upper 2 assembly has a 16" Parkerized barrel, 1:7 twist rate and free float quad rail. This complete upper receiver is chambered in 5.56 nato and machined with M4 feed ramps (both in the lower and barrel extension) and comes with a BCA BCG and charging handle. This is the perfect upper for your next build. The BCA Kodiak upper 2 assembly, like all BCA products, is subjected to numerous QA/QC checks which for our firearms and upper receiver assemblies includes test firing prior to approval and shipment. This upper assembly is also backed by our BCA limited lifetime warranty. Choose an upper assembly designed by a U.S. company and made in the U.S.A. Choose BCA. BCA DOES NOT recommend using steel cased ammo in our Assemblies or Rifles.