Just back from trying some more loads in the 416Rigby.

AR2213SC (AKA Hodgdon H4831) 106Grains behind a 410 grain Bertram SP 2460fps

AR2213SC 104 Grains behind a 410grain Woodleigh 410 Solid 2480fps

AR2209 (AKA Hodgdon H414/H4350) 98 Grains behind 410 Bertram SP 2450fps

AR2209 90Grains behind 450Grain Woodleigh RNSP 2250fps

The 450 hit 2 inches lower at 50mts all the rest were in the same group.
With the 450 grain pills I am working without reloading data but I can still go higher in velocity going by the case's and extraction but why bother.

All these were out of a 26" barrel on the CZ550. I found my thresh hold for shooting this off the bench 16 rounds. Next time might take a longer break between loads, like 20mins instead of 3.

Cheers
Greg