Cheapest way would be to adopt improved magazines such as pmags and adopt the Mk262 round.
You solve the vast majority of malfunctions using quality magazines and already there are better bullets that can be used so reinventing the wheel just to have something new is not the answer. We're not going to a new caliber anytime soon given the current economic outlook and our allies will have to adapt the caliber also and their economic outlook is even worse.
Piston uppers have shown only to be effective for SBRs and suppressed SBRs and will not be effective for the general soldier so why buy something new that is really not needed?
You solve the vast majority of malfunctions using quality magazines and already there are better bullets that can be used so reinventing the wheel just to have something new is not the answer. We're not going to a new caliber anytime soon given the current economic outlook and our allies will have to adapt the caliber also and their economic outlook is even worse.
Piston uppers have shown only to be effective for SBRs and suppressed SBRs and will not be effective for the general soldier so why buy something new that is really not needed?