Ok, so I think I've decided it's time to give it a go with mounting a PE scope on a mosin. I just got a Finn M39 with a PE rig on it (see mosin hq forum), and I really like it so I think I want to do my own 91/30 PE setup. I have all the proper equipment really (quality drill press, carbide bits, etc). My question is, on the two front screws on either side of the receiver (the two closest to muzzle end of rifle); if I drill a bit too far and go into the barrel a little, will that render the rifle unsafe to fire? I don't mean going balls-to-the-wall and driving the bit right through into the chamber, that of course would not be good. What I'm talking about is just going into the meat of threaded part of the barrel a bit. I'm confident in my ability to the point where I don't think it will happen, but if it does I'd like to have a little "before-hand" insight.