What would have happened if British Major Patrick Ferguson instead of inventing the OTL Ferguson Rifle with its complex parts and easily fouled breech screw, invented a falling block breech loader like the sharps rifle and carbine of ACW fame? Would it be a simpler and more reliable mechanism, and so make it the weapon of riflemen even if it didn't effect line infantry, or would it still be too expensive and complicated to have a significant effect on firearms at the time?