Two things that would concern me: functioning and bullet integrity. With regard to functioning, does the SWC work through the lever action? With regard to bullet integrity, how hard is your 215 grain SWC? How fragile is the Remington 210 gr HP? if the Remington HP is made to open at speeds typically obtained with 4" - 6" revolvers, how will it perform at the increased speeds from the carbine?
