Shoulda stuck with the .45-70.
Our special forces actually used a modernized version of .45-70 in a specially chambered M-4 system for close quarters entry applications and blowing doors off their hinges.
They call it the Alexander Arms Beowulf .50
They loved it when it worked but it was unreliable in full auto in the M-4 so they moved on.
Great minds . . . :-)