It's Physical, but it's the only real coverage move it has. However, you're not really going to level it up at Victory Road, so you will only ever use it against underleveled opponents, where it is adequate.Ya Thunder Punch loss was bad for him. But really Top Tier ?
Isn't Magnet Bomb physical ? Magneton without Magnezone is sad ... Especially when he doesn't have the attack of Magnezone for Magnet Bomb / Gyroball and Flash Cannon is not available until Cerulean ( I don't count the TM in Goldenrod Department Store because luck is involved)