I had one of their x39 uppers and it was awesome. I've a 4" popper that I never missed at 250 yards with Tula x39 ammo. I mean you know going in it's cheap blaster but was accurate enough and I never had a hiccup and like psa, you have people with no issues and people with issues. That said, I posted two links and if that gun was DD, BCM, LMT, etc, people would be saying that's why you buy qualityOK.. Not saying .. they 'BCA' don't have the worst QC inspection, and don't do low-end builds . also I have never shot or owned one of BCA in-house builds either. I have only bought their Uppers.
I just switched-out Uppers on one of my AR's. With one of BCA's, and put the 1st Round threw it today .
I re-bedded the same barrel on the BCA Upper, put it together, and threw the same scope on it that was on the last Upper with the same Zero @ 100 .
I put up target @ 50 yard to start to put a new zero on. The 1st Round was dead nuts on Wind as on last Uppers Zero, and 2" high @ 50 yard.
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not a bca defender but again, you know you are buying a 200 complete upper so you can't expect the tits.