Barrel nut out of spec, manufacturer response appalling - JL Billet Angle Cut AR-10 M-Lok Handguard

The barrel nut was poorly machined, and it was clear after measuring it that the CNC machine cut the exterior diameter slightly cone-shaped. The section closest to the upper receiver was over 10 thousandths out of spec, and it interfered with the gas tube to the point that you couldn't even install it.

The manufacturer was borderline indignant about all of this, and they tried to blame the Cerakote, which is dimensionally insignificant. They begrudgingly sent a replacement barrel nut, and threatened not to warrant it if I coated it again, which is technically illegal according to federal law (Magnuson-Moss).

I'll never buy anything from these people again. You poorly machine your parts and then try to offload the blame onto the customer? Un-be-lievable...