Well, other than screwing up your barrel, you will lose velocity because of that hole, the air that is propelling the paintball forward will now go in two directions instead of one, and you will lose power, speed, accuracy, and velocity in one fel swoop. It also depends on what barrel you are using.
You can drill holes in aluminum with a drill as long as you have the proper drill bit. Use a regular drill bit and keep speed moderate.
A drill makes holes in things.
To drill holes
The Drill Press is used for drilling holes in various materials.
Drill bits are for fitting into a drilling machine to drill holes.
Drill bits are for fitting into a drilling machine to drill holes.
You can drill very accurate sized holes, you can drill very large holes with the use of hole saws, you can drill many identically placed holes, with use of jigs you can drill holes in many sheets of thin materials if clamped together, you can drill large holes in very thin materials with use of a fly cutter, you can drill holes to a precise depth with Forstner bits. you can mill things flat with milling bits and many more things - a drill press is a very versatile machine
A pillar drill is used for larger holes, more exact placing of holes, or drilling repeated holes with a jig to insure uniformity.
and hand drill drills holes into woods
used to bore or drill holes in the PCB
Because it was a faster way to drill holes.
The function of a drill is make clean holes in objects.