As per previous post, if you go for a scope
get a Leupold 1.5 - 5 or something like that
for the long eye relief + it's tried and tested
on big bores.

Don't over power the scope.

Make sure if you put a scope on it is in QD mounts
and that your bullets shoot to the same point of impact
with both the scope and open sights (this is easy to achieve
with any gun).

The only time I can see you using 505 on longer shots
is if using the gun on a running wounded animal that is
getting away.

I wouldn't be shooting past 150 yards on the first shot
with a 505 Gibbs.

Also - decide whether you will use 525gn or 600gn
bullets or make sure both shoot to the same point of impact.

Good luck.

500 Nitro