All good comments. The barrel isn't bent.
First, I'm going to try American made 8mm ammo, b/c hopefully it's loaded to different pressures. I know Remington is loading 8mm Mauser again for 2003. Second, I'm going to try the Austrian ammo from Samco, NC and reloadable, so many pluses there. Third, I'm going to replace the front sight. And lastly, I might get the barrel slugged to see what the actual bore diameter is, maybe the bullets are rattling down the barrel. Before any of this though, I'm going to disassemble and put together again to see if that helps. I hope it's ammo.
I'll keep you posted.