So I got a new ar upper assemblied by Curts Discount shooting supply. *Anderson Upper *Fail Zero nickel boron BCG *Odin 18in .223wylde barrel mid length *Odin gas tube and gas block *A2 bird cage *Am Tac 15in free float rail Lower is a spikes tactical with a ST-T2 buffer and geiselle ssa trigger I finally got to shoot it today and it kept have FTEs (mainly) and sometimes some FTFs. In order of most occurrences Empty case is only 1 inch extracted from the chamber Bolt did not move but round was fired Bolt cycled ejecting the spent case but failed to strip a round from the mag, chamber is empty Bolt failed to have enough momentum to strip or fully strip a round from mag Spent casing stuck on the lugs of the barrel Got me confused. I've tried switching to the M16 BCG from my 14.5in med length upper and running the nickel boron in the 14.5 and the M16 in the 18in but still problem occurs and the 14.5 had no problems. I have over 25 P mags 30rd both gen 2 and 3. 1 20rd gen 3, 1 40rd gen 3, 1 tavor mag (caa), and 10 Blackhawk! 30rd gi mags. Using M855 green tip brass 5.56 62gr, 62 and 55grain wolf steel case .223, Fiochi 62gr 5.56 brass, PMC .223 55grain brass. All rounds and mags did not work in my 18in ar but ran flawlessly through my 14.5 and my tavor. I tried cleaning it after the first few mags and putting light lube, no different, tried extra lube, no difference, fired over 200rds no "break in" difference. My conclusion is that the barrel wasn't installed properly, but I doubt that due to Curts reputation of excellence. Or the buffer is the improper weight. Anyone else have any idea what it could be?