Noveske, BCM, or Spikes? I have a bcm upper on a noveske lower…
http://shopnoveske.com/collections/parts/products/rca-low-mass-carrier-group
http://www.spikestactical.com/bolt-carrier-group-spikes-nickel-boron-hptmpi-m16-bcg-556-p-388.html
http://www.bravocompanyusa.com/BCM-Bolt-Carrier-Group-MPI-Auto-M16-p/bcm%20bolt%20carrier%20group%20auto%20mp.htm
I like the upgraded coatings… But I’m not sure if the noveske also has the upgraded springs and o-ring, which is a plus for me.