I shoot a .460 Weatherby built on a CZ 550, with no brake, pretty much each time I go to the range. It doesn't bother me until I start hitting max loads with the 600 grain bullets. I usually do 5-10 shots each range visit, no bruising and no headache.

I have also shot some really big ones like a .505 Gibbs, .577 Tyrannosaur (loaded to 750 grains at 2200 fps), and a 606 Mammoth (I think it was somewhere around 850 grains at 2100 fps). The range session with those gave me a headache and lightly bruised my shoulder. With enough practice though, the headache and bruising should disappear.