There's the chance of a ricochet, possibly into the body of the shuttle or bystander. Or they miss, hitting whatever was on the far side of the shuttle. I think

There's the chance of a ricochet, possibly into the body of the shuttle or bystander. Or they miss, hitting whatever was on the far side of the shuttle. I think it would also be not as controlled a release of air as they'd want - the drill bit shown is much smaller than a rifle bullet. And a bullet would add it's own energy to the mix.