Yes, it is in the archives all ready. I found it without the archives and i think my way is much easier. This one is much faster and the person doing the glitch will be able to see the gun fly away as well. Instead of picking the gun up at the same time, have the monitor pick the gun up repeatedly by pressing the A button as fast as they can. Have the other person hold the RB button over the gun. This is a lot easier than picking up the gun at the same time.
If done correctly, the person should be holding the gun in its normal position and the monitor will also be holding the gun (the cursor will be green and the fist will be closed). For the person that does the glitch to see it immediately have them run at a gun of a different type (you cannot all ready have the gun on the ground) and when they run at it hold RB so they throw the gun in the air. The gun will float through the air and spaz out at times. The gun will only drop if the monitor goes out of forge mode (back into human form)
I have done this with every gun. The easiest are the needler and rocket launcher, hardest are magnum and sword. The needler and grav hammer look the coolest. Doesnt work with weapons that go into third person mode to the extent of my knowledge(MGT, Flamethrower, Plasma cannon)
You can also shoot the guns in mid air to make them go where you want them to.

Enjoy