The problem with subcontracting critical parts to companies that don't know the consequences of their decisions is rife in small arms production. They think their changes in steel or process won't matter, but watch out! The receiver of the British L96A1 sniper rifle was specified to be machined; except the aerospace contractor thought they knew better and cast it instead. The designers could not easily convince them that their decision was fundamentally dangerous to the shooter, and only with great difficulty showed them.
https://www.youtube.com/watch?v=Z-j3Isreqbg