04-03-2021, 01:38 PM
The BCM receivers get very good reviews and usually need a thermal fit to get the barrel seated. Basically BCM receiver have close tolerances and manufacturing quality. With a forged upper your paying more for name brands and the possibility of tighter control on tolerances. I use a lapping tool on my upper receivers and use blue Permatex to coat the barrel extension when mating it to the receiver. I have used RRA, DPMS, Double Star, PSA, Anderson and CMMG upper receivers. All have been fine but Ive never used any billet receivers.
Some receiver brands have different styling and other than a slab sided DPMS upper receiver on a 22 LR upper all my receivers are mil spec A-4 flat top receivers. Ive mixed different brands of uppers and lowers and have never had a problem. Some times the exterior finish is not an exact match between upper and lower receivers. Exterior finish can differ slightly between examples from the same manufacturer and is not an issue to me.
Some receiver brands have different styling and other than a slab sided DPMS upper receiver on a 22 LR upper all my receivers are mil spec A-4 flat top receivers. Ive mixed different brands of uppers and lowers and have never had a problem. Some times the exterior finish is not an exact match between upper and lower receivers. Exterior finish can differ slightly between examples from the same manufacturer and is not an issue to me.