The 458 Lott in the Mk II is fairly easy to shoot IME. My main complaint with the rifle which I only recently sold, is that the stock especially the forend, is too blocky. The weight was not the problem, it was the handling due mainly to the weight distribution.
If I ever get my hands on a MK II again, it'll become a Gibbs-based .510 'wildcat' that'll fit in the 3.6" magazine. Then there'll I'll have no complaints about the weight!
