Ok, finally shot the Arisaka with 1940's dated 30-06 surplus ball ammo, at a target.
First the max range I could shoot was about 30-35 yards, so not a real good test of the accuracy.
I was shooting at a medical oxygen cylinder (empty) at the deer lease. Frontal area about 5 inches wide. I was able to hit the target with every shot on the tank body. Real good penetration, with good sized exit holes on the rear.
After a few rounds I targeted the neck of the bottle and the 1 inch wide valve on top. From 25-30 yards every shot hit, except one which I know I pulled off to the right (no fault of the gun). First shot at the neck left a significant dent in the thicker metal, second did the same. Third shot at the top of the valve knocked the top clear off, Fourth shot at the base of the valve, above the cylinder top, launched the valve deep into the woods. All shooting was off hand, no rest or sling.
So my assessment, I would trust the gun and ammo combination out to about 75 yards on deer sized game. If I were to want to hunt a longer distance, I would take it to a measured distance range and put it on a bench to better check it's accuracy.
It's been good to shoot the gun, and find out it's quarks, but I will probably clean it, and store it for good. I am fortunate enough to have better options for shooting and it's now a novelty. As a family heirloom, I will keep it in the family and pass it on someday.
Only problem, bolt hard to retract after shooting. No signs of over pressure on the spent casings.