A good brake will tame most magnum rounds. I personally dont like to shoot above 7mm Rem Mag unless they have a brake.
I have shot a 300 win and 300 weatherby before and after a brake, and the difference is night and day. Neither 300 was fun to shoot before the brake, but after they are nice soft shooters. The 300 weatherby is a sporter barrel so it isn't that heavy, but with a nice 3 port brake it is tame. The heavy barrel 300 win mag with a 5 port brake shoots almost like a 243. They are loud as sin, but I will take that over the recoil.
I have shot a 300 win and 300 weatherby before and after a brake, and the difference is night and day. Neither 300 was fun to shoot before the brake, but after they are nice soft shooters. The 300 weatherby is a sporter barrel so it isn't that heavy, but with a nice 3 port brake it is tame. The heavy barrel 300 win mag with a 5 port brake shoots almost like a 243. They are loud as sin, but I will take that over the recoil.