The Double-Switch

Double-switching weapons is one of the most used (and most useful) techniques in CoD4 Promod, though it is used frequently in stock CoD4 as well. There are many advantages to doing this; we will cover some of them below, as well as the basics of how to do it.

What is double-switching? Essentially, it is exactly what it sounds like: switching weapons twice in rapid succession, causing your second weapon to not raise and the original to become active again. There are several ways to accomplish this; the one you use likely will depend on personal preference:
 * 1) Bind "weapnext" to two different keys, and press them near-simultaneously (they need to be around 2ms apart; if you press them at exactly the same time, it won't work).
 * 2) Script it. Keep in mind this isn't allowed in most leagues/on some servers. Open console (~); type */bind 1 "weapnext; wait 2; weapnext"* (replace "1" with the key you want and without the *s).
 * 3) Bind "weapnext" to your mousewheelup or mousewheeldown and simply scroll 2 clicks. This might be more difficult depending on how precise your wheel clicks.

What is it used for?
As mentioned above, there are many uses for double-switching.
 * 1)  Reload Canceling : This is the oldest and most well-known double-switch feature. While similar to reload cancelling by sprinting or knifing, double-switching is superior because you don't have to wait for either your sprint to stop or the knife animation to finish before you can start firing again: your gun is ready *immediately*. Reload canceling works because all guns have a difference (some more than others) between their ammo "add" times and the length of the reload animation. This difference is generally greater when reloading empty guns due to the cocking mechanism (the M4 and M16 are two exceptions; there's very little difference). The primary guns of Promod (AK47 and AK74u) happen to be two of the best guns for reload cancelling; their "add" times are short enough that a player with even half decent timing can stop the final "crunch" of the clip being shoved into the gun. Also, you can reload cancel in the true sense of the word: stop your reload part-way through if for example you see an enemy, and immediately be able to fire the remaining bullets (if any) in your clip.
 * 2)  Re-chamber Canceling : The pump shotty (W1200) and bolt-action snipers (M40A3 and R700) have an interesting characteristic that isn't present (or isn't applicable) to any of the other weapons: re-chamber time, or the time it takes from when one bullet is fired until the next is ready. However, just like the "add" time differs from the length of the reload animation, the re-chamber time differs from the re-chamber animation, meaning it can be canceled! While the effect is not as dramatic for the snipers as in stock CoD4 (the rechamber time has been increased for them in Promod), it is still of some use for getting shots off more rapidly. It takes a bit of practice to be able to "feel" when you need to double-switch; do it too early and you're stuck activating the bolt mechanism again. The W1200 can also be made to shoot quite rapidly with this method, but no one really uses it in Promod.
 * 3)  Pickup Canceling : I'm not sure of the "proper" name for this, but I'm referring to the cocking animation that takes place on some of the weapons when you pick them up. Specifically for Promod, both the AK47 and AK74u are affected. This animation is completely pointless and accomplishes nothing but waste time, a perfect candicate for double-switching. Simply pick up the weapon, double-switch, and begin firing immediately. Depending on your skill, picking up a weapon you're standing on or near to with this method might actually be faster than switching to a pistol!
 * 4)  "Raise Time" Canceling : All weapons have a raise time: this combined with the drop time of the weapon you're switching from gives you the total time between when you drop a gun and when the gun you're "raising" is ready to fire. You'll notice that pistols have a much lower raise time than most of the other weapons. However, like so many other things, raise time can be canceled. It's a bit difficult to explain, but it basically works like this: the gun that is "active" (i.e., the gun that you currently are holding; if you're dropping it and it's still during the "drop" time, it's active; if you've dropped a gun and are currently "raising" another, that one is active) can always be fired immediately, as long as it has a chambered round. This means several things. 1) If you've single-switched to your other gun but your current gun hasn't "dropped" yet, you can single switch *back* to the gun that's in the motion of dropping and fire it immediately without having to wait for it to "raise" again. 2) You can cancel the gun's raise time you're switching to. You can take advantage of this as follows: single-switch to start the drop animation; as soon as the weapon is "dropped" (near where the weapon switching sound is), double-switch; the gun you switched to is ready to fire immediately, without waiting for raise time to complete. 3) Raise time also comes into play when sprinting (and jumping while sprinting). You can double-switch immediately after sprinting to make your gun instantly fire-ready again. This can come in handy if you tend to sprint and strafe-jump around corners. Normally, you wouldn't be able to fire immediately at any enemies around the corner (until raise time completes), but if you double-switch shortly after leaving the ground, you can round the corner with your gun up and firing.
 * 5)  Other advantages : Those mentioned above are the main advantages of double-switching. Some think that rapid double-switching slightly increases your sprint time (is this true??). Also, you will find many players that just do it all the time as they're moving around the map; this has no positive or negative effect, it is simply out of habit. I'm unaware of any other benefits to double-switching. If you have it bound to the scroll wheel, you can use it as a kind of cheat for scroll firing for semi-autos (hold down left mouse while rolling the mouse wheel), but this has no practical use in Promod with the fire-rate being limited.