Here wo go what I did:
Got a second hand CZ550 in 416 Rigby complete with Leupold 1-4 scope for EURO 850.00
Made up some handloads with copper clad lead bullets (see thread here somewhwere) in order to get accustomed with it. (350grs at 450m/s or 1500 ft/s) About 1 moa groups at 50 meters were good enough for that. It is shooting like a smallbore.
Next step for plains game worked out a reload with 350grs Speer bullets and 84grs of Vihta N160 in Norma cases. Chrongraphed they were way below published Lapua figuers only clocking 650 m/s or about 2130 ft/s.
In the meanwhile I got a can of N165 powder and made cartridges with the same bullet and 86 grs of this new powder. Same velocity,
then stepped up to 95 grs of N165. I didn´t yet measure them but expect them to be around 700 m/s or 2300 ft/s.
It was no big problem to make 10 or more shots of those rounds in the sitting position. They definitely are not made for prone shooting though.

If you want to have cheaper brass and accept belted cases go for the 416 Rem.