People who imagine wars in space need to Kerbal more.

A bolt in low earth orbit is traveling at 8 km/s just to avoid falling, and if it's moving in a retrograde orbit to you, that's 16 km/s. You're talking 6 to 10 times faster than the fastest bullet. Fire a bullet that fast at sea level and it will vaporize in the barrel and probably take the barrel with it.

What do you need to make a space weapon? A box of ball bearings and a rocket to throw it to orbit. That's it. Get it vaguely in the general direction of the target and you've got a good chance of not only destroying the target, but causing kessler syndrome for the next couple decades.