har1340 and TaylorWSO The guide rings on the newer style HK21E/HK23E springs will not fit into the older HK21 bolt carrier without slightly turning down the guide rings. The guide rings are easily removed to replace the springs as needed or customizing. I think I got this tip from Ralph at RDTS. Works perfectly and pretty smooth.
Last edited by djohns11; 11-15-2019 at 01:16 PM.