A 7.62mm = 30 caliber. So a 30-06 is a 7.62 in caliber. HOWEVER the 7.62x39 is NOT the same as a 30-06 round. 7.62x39—with a much shorter case.... was designed for close action and is between a classic rifle round and a pistol round. It was intended for close action combat, but not accurate over 100m.
A 30-06 in AN M1 Garrand on the other hand, IS high powered. Russian ammo sizes are also found in 7.62x54 (with a longer case=more powder) which is comparable to a 30-06, and is considered “high powered.” The common Mosin-Nagant uses that ammo.