I don't have a glass drill bit atm and its going be awhile until i can have time to get it . What can i use instead to make a hole? i got a coke bottle or a glass milk carton i can use right now.
Really if you're going to put holes in glass, you're going to need a diamond coated drill bit. I don't know of any other way. I did hear of a method where you put a nail in the bottom of a glass bottle and give it a quick shake and the bottom comes off. But I've never tried it and it doesn't sound promising.
Imo there's absolutely no point of making a glass gravity bong, just use a fucking plastic bottle! Diamond bit as Axeman said...