This thread is about a special type of jump called the gun-switch jump that roxzor.of.sorts and I found. The simple explanation is that if you switch your weapon while your strafing up to your jump, you gain a speed boost. During the duration of the gun-switch, it appears to me that you don't have any weight at all to keep you from running at full speed. This in turn causes you to gain a boost of speed, and when combined with a strafe jump, can cause you to jump further.
Now, some interesting points have been brought up (mostly by Drofder I believe) that different weapons allow you to run at different percentages of the full speed. He also stated that there appeared to be no difference in your weight during the process of switching your gun. This seems to be enough valid proof to debunk my claim, but I believe that something allows you to run faster during this time interval.
I really have no interest in the Call of Duty series anymore, so I'll ask you guys to try out this theory. I haven't played the game I originally tried it on in a very long time (CoD4), so I really can't tell you first hand if it even works anymore, or if it works in any other games in the series. If you would like a tutorial, I can most likely arrange something with some community members who might easily pick up on this idea and be able to explain it to other people, so that we could make a video to be posted on youtube.
But for now, I'll give a simple text explanation of the whole process that worked for us when we used it a long time ago:
-Set up for a normal strafe jump by facing at the angle your comfortable with from the ledge you wish to jump from.
-Take out your primary weapon and prepare to strafe.
-Press whatever button you have bound to switch weapons at the same time as you begin the arc for your jump.
-Jump as you would a regular jump, allowing your character to continue to switch weapons in the air if necessary.
Its as easy as that. It might take a little getting used to this method, as it appears that the speed boost only occurs when you are in the process of switching weapons, which might require you to do your run-up than usual. We also found that switching from your main weapon to your pistol worked better because it took longer than the other way around (but i might have that backwards, whichever takes the longest we found to be the best way). Also, we found that certain combinations of weapons were better to use than others:
From an SMG to a pistol worked fine, as well as vice versa.
From a Sniper to a pistol worked fine, as well as vice versa.
From any weapon to an RPG DID NOT work fine. For some reason we found this to only slow down your jump.
Other than that, I have no idea. It's all up to you guys to either make new discoveries with this, or completely debunk my hypothesis like Drofder has already started

Oh yeah, and after you give this a try, please leave any feedback in this thread. I will also gladly except any game engine related explanations as to why this does or does not work.