I’ve built my fair share of AR-15 rifles over the years. Just one or two (hundred) short of fellow contributor Tim Stetzer, but I’ve gone through several lower parts kits—some good and some not so much. The main ones I’ve gone back to were from Anderson Manufacturing (RIP), Aero Precision (life support, but may be back?), and CMMG. All have worked as intended. None are expensive, and all have been fine—nothing to move the needle.