Similar to the BXB trick, BXR is a Halo 2 glitch that will help greatly in your close combat struggles.

BXR Glitch

Your gun must be fully loaded for this to work. Push the buttons B, then X, and then quickly push R (the right trigger button). There you have it - a punch and then an immediate gun shot. When this technique is performed with something like a battle rifle shot at the head, it can be very damaging.

Bonus Tip!

BXR works with any gun.