I had my reservations at first, but after some research, speaking to a couple people familiar with the platform, and a thorough inspection, I'm confident the rifle is in good shooting condition.
I really like getting behind these old rifles every chance I get. Gives you a sense of the skill it must have required for a soldier to become proficient in shooting them. Most of the time I can't hit anything past 100yd...
Here are some shots of the 7.7 x 58mm (middle) compared to a .30-06 (left) and a .308 (right)...
The round uses the same projectile as the .303 British. Most commercial ammo uses a 150gr bullet which pushes muzzle velocities in the neighborhood of 2500-3000 fps. Cases can be made by resizing .30-06 brass...