I have a couple Colt made HK416 Bolt Carriers. $200
These carriers were pulled from the Colt IAR piston rifles and had been converted to use in the 416s. They work just like the Brownells carriers. They use any standard AR15 bolt head and BCG parts. These have been tested in post sample HK 416s without issue.
This is perfect for any range with a rental 416. Dont worry about blowing up expensive HK bolts!
For more pictures or a video of testing text me 615-418-8181