Somewhere between 7-8 lbs on an all around rifle and closer to 7.5 seems just about perfect. I don't shoot anything over 8 lbs any better and even 8 lbs isn't too bad to carry in even the toughest terrain. I'd probably prefer a bit more weight on a heavy recoiling rifle and I have a Kimber that is still under 6 lbs scoped. But I tend to reach for the ones in my safe that are 7-7.5 lbs most often.
