Has nothing to do with feeding. To my knowledge Barnes was sued or threatened with court action by the Feds because of the FP monolithic bullet. The contention was it tended to penetrate some forms of body armor. Barnes has not chosen to fight that battle and has decided, for now, to stay with the RN. Who knows the future? The choices for FP monolithic solids is limited. I think CEB makes mostly brass versions and limited copper versions. North Fork makes copper versions. One or two other companies make some form of FP monolithics but may or may not be currently available. One of the best was designed in RSA and actually moved some production to the US. That was GS Custom. Info has it they got shafted by Chey Tac and there are no plans for restarting production. IMO, the GS Custom, Rhino and North Fork are three of the best copper monolithic FPs ever developed. Currently North Fork is available in limited quantities from Reloading International. Rhino is an RSA company and to my knowledge not currently available in US. If you want a brass monolithic, check out CEB- they make a lot of brass styles but seem to be more limited with copper. Additionally, many of the monolithic bullet companies have chosen to chase the long range "sniper" market with extreme BC type bullets and seem less interested in DG FP hunting bullets. That's my subjective observation.