Hop-

The barrel flats don't specifically discuss the proof load or service load for this rifle besides noting that it's set up for jacketed bullets in the 8x60 cartridge.

From there it's pretty safe to assume it was meant to run bullets in the 200gr neighborhood at about 24-2500fps out of it's 28" barrels.

I don't have the chrono information handy for the good load with this rifle, but I can tell you it's a .318" bore and the only decent bullets I can seem to find for it are the 198gr Woodleigh SNRN which do work well.

I'm not eager to try to push 220gr bullets at 2800fps in this rifle.

--Tinker