The exploit was featured in the AGDQ 2014 Borderlands 2 four-players co-op speed-run. I think it involves a skill of Axton (the Commando) that speeds up his ADS movement, which is manipulated and stacked to allow him to move at Sanik speed.
The speed glitch is accomplished this way:
- You must use Axton (duh)
- You must have at least 1 point in Expertise, in the Gunpowder skill tree
- You must have at least two weapons to do this
- You must be in a Multiplayer session, and you CANNOT be host
Some other tips when starting this:
- Having a full backpack will make the process of the glitch much more quicker and simplified
- Having more points in Expertise (either via mods or skill points) will make the process quicker to achieve.
Going over the skill in general:
- Weapon Swap Speed: +14% per level
- Aim Speed: +14% per level
- Movement Speed (while aiming): +7% per level
How our glitch works is this. Since Expertise will only increase the movement speed while aiming down the sights (or scoping in), you need to have one gun on the ground, and one gun in your hands.
Normally, if you find a weapon, you can press E to grab it, just like any other item. Now, if you hold E when you find a weapon, you will automatically equip it.
So to perform this glitch, we need Axton to switch weapons while aiming down the sights. This is why previously, I have mentioned that you should have a full backpack, so that pressing E doesn't collect the weapon on accident.
- Aim down the sights with your current weapon
- Look at the other weapon on the ground. You must be within "reach" of the weapon for this to work
- Hold E (or whatever you have binded "Equip" to)
- Repeat Steps 1-3 as many times as you desire.
As mentioned before, having more points will make accumulating speed boosts much faster. So if you wanted to hit, say +210% movement speed, with only 1 point in Expertise, you'd have to repeat the process far more then say having Expertise at 5 (or more).
Axton speed glitch is done from an off-host player, this is because there is something built into the game to make connections to hosts more efficient. Using the skill Expertise a player can stack their ADS movement by throwing their gun while looking down the sights. This can be done how ever many times you wish.
This exploit can only done off-host because connecting to another player changes character saving from the Single-Player method of saving all the character data at once (including whether the player is looking down sights.) to the Multi-Player method of sending status effect and some player data to the host. (Including speed, but not whether their looking down sights. That's why it stacks when they ADS again.)