Alright, so I'm in the middle of converting a Classic Army M15A4 into a Patriot styled CQB Weapon. For those who don't know of it, I'm converting it into this: http://images1.wikia.nocookie.net/__cb20100912172050/metalgear/images/c/c1/Patriot2.jpg Now, I've unscrewed the Buffer tube cap. I've taken out the big, long screw in the buffer tube, and taken off tube, screw and plate, leaving the receiver itself, which has a small protrusion. I'm fine with that, it's part of the gun anyway. But here's my question: The long screw appears to enter into the gearbox. Will the removal of this affect the gearbox? Would this prevent the gun from firing reliably? Or is it just that there was nowhere else to drill the screw into, so CA just put it in through the gearbox?