Not good. That drill can do 2500 RPM and the speed control is not done via gearing but some type of voltage control. You'll end up having to run the mill too fast to get the torque you need. The better corded drills are those rated for a lower top speed or ones with an adjustable gear box.
The Harborfreight has a max of 600 RPM so the 200-300RPM range you'll want is at a much higher trigger pull.
The Harborfreight has a max of 600 RPM so the 200-300RPM range you'll want is at a much higher trigger pull.