Casper:
A suggestion you might consider is to have the barrel profiled to leave near full diameter between the receiver-ring
and your forward hand, then taper swiftly to an absolute minimum wall-thickness to the muzzle.
That way the remaining weight will be concentrated close to centre of mass, and the rifle will
probably become lively enough to use in the hunting field.

Can't believe the unnecessary barrel wall thickness at the muzzle! Its just a 10-bore bore-gun, for goodness sake!
Madness!

Ha! Posted on top of you, RB.
Great minds think alike...