I generally don't recommend any bushnell scopes below the Trophy line, especially on harder kicking rifles.
In the meantime, yes, send it back to Bushnell for work, but do yourself a favor and get an Elite 3200. Although on a 45-70, I would also side with Redhawk and get a Leupold VX-II.
You lost a 160 class deer because of a cheap scope. Would you consider that deer to be worth $250? If yes, then just buy a better scope.
Zachary