I have a Model 98 custom Mauser that is chambered in 30-06 Ack Improved. Came to me so chambered. It is very accurate, while improving velocity about 100 fps over 06, with 200-220
gr bullets, and 1 MOA with earlier Barnes 225 gr sspitzer bullets. Nosler 220 gr partitions and 220 gr RN Hornady also work well.
It likes heavy bullets, and this puts the 06 AI in the class with the 318 nitro express rimless Westley-Richards -early Mausers in Africa. It has a Bausch & lomb scope.
Most 06 AIs prefer heavier bullets, with quicker twist rate rifling.
Each rifle is a law unto itself, and maybe I was fortunate to get a real performer.
Looking at the classic stock, scope, and barrel ramp sight-I think this rifle was made in the late 50s or early 1960s.
Have been able to load cartridges using fire-formed 06 cases, a .308 neck sizing die-along with a spare seating die from a
338 WM RCBS die.set. It works.