Borderlands 3

THE FASTEST WAY TO DO THIS. TAKES ABOUT LESS THAN AN HOUR.
I started out trying to fill USE all the extractors (3 on the surface which can only do 3 items each and just once, and 1 down below which can do 5) and one run with all the killing and running around took like over 30 minutes so it would have taken over 4 hours to do this this way.
Instead do this. activate the green teleport orb (as it is counting down just go and stand where it appears that way you instantly teleport). Once you teleport and are falling look down and see where the items box is where you land and spin so you are facing it when you land. Open it and grab those 4 items usually 2 guns and 2 shields. Now open you map up and find the closest extractor to you and now run to it ignoring all the enemy spawns just run past them, I never died or got put down once ever doing this method. Once you get there put in 3 items and extract them (just spam the A-button). Now run over to one of the enemies and have him kill you, their melee attack is pretty powerful usually just 3 to 4 hits to put you down, now press X-button to kill yourself fast and you will reappear in the control. Now just rinse and repeat. I was extracting 3 items each time in less the 2 minutes SO DO THE MATH. You occasionally get lucky and an extractor is close to your drop location but usually it is a bit of run. HOPE THIS HELPS.
Oh VERY IMPORTANT the items that you extract are placed in your safe on Sanctuary (I initially thought they were moved to the control room where you teleport from so you could gear up before teleport I was wrong). As such there has to be room in the safe for these 100 items so if your safe is full or almost full it will only extract items till the safe is full then all extractions will STOP, so make room for 100 in your safe. If you are playing multiple characters then have them move items into their backpacks (maxed out backpack will fit 50 items) so you do not lose anything. Once you are done just sell all those white items at Marcus's and put your items back in the safe.

Bunny Breakfast comment. This only works for SINGLE PLAYER seems COOP does not help for this. Thanks

This achievement really isn't as bad as it may seem, just slightly grindy. Through out the Stormblind Complex, you will find 'Gear Extractor' machines (On the map the symbol for them is just a Arrow pointing up in a diamond). Each one of the machines, you can extract a handful of gear at a time (3 slots in machines found round randomly the map, and 5 at the final machine once you finished the Arms Race), and since there is 4 machines each run of the Arms Race, you can get around 9-14 weapons per run if you're lucky.

Main thing to focus on when jumping into an Arms Race is finding gear, you can get gear from killing enemies (melee does a fair amount of damage) or by looting chest containers. There will always be a chest close to you when you drop in that will have gear, so make sure you loot it to make going to other extractors/getting loot easier for yourself. It does not matter what rarity of the weapon it is for the achievement, all you have to do is place the gear into a machine around the map, place the gear into the machines, press the 'Extract' button in which you'll get a prompt confirming the extraction. Once you press 'Yes' for the extraction the the gear will be extracted so meaning even if you do die, that gear will still be extracted and adds to the achievement total.

To make this go as quickly as possible, it's suggested that you kill yourself as once you finished the Arms Race, you will need to either back out to main menu and come back into the game, or fast travel elsewhere then travel back into the Stormblind Complex to restart the arms race. If you die before you complete the arms race, you will respawn at the start of the Arms Race with all your gear gone that you had in your inventory (any placed into extraction machines will be extracted still). So once you're happy that you've extracted enough weapons into as many extraction machines as you can, just let an enemy kill you or find a way to kill yourself and repeat the process until you have extracted 100 pieces of gear for the achievement! If you're using this strategy you should be able to get up to 9 pieces of gear each run. You do not lose any money when dying in Arms Race so no need to worry about losing money with the dying stratergy.

Alternatively if you do complete the arms race, there is a Extraction machine right by the Fast Travel Machine in the room behind the boss which will have 5 slots, and if you manage to use all 4 machine in one run of Arms Race you'll be able to extract 14 weapons at once. This 'may' be a quicker strategy on Series S/X with the faster loading times, regardless killing yourself saves you the job of fast traveling away and coming back after each run.

*NOTE* Make sure you have space in your Bank. All gear extracted from Arms Race goes directly into your Bank, and once your bank is full of weapons, you will be unable to extract any weapons until you make space in your bank.

*NOTE 2* Few people have reported that the amount of gear isn't tracking when playing with others. For the best chance at the achievement, it's recommended that you play SOLO (or very least host) in order for the gear to be calculated correctly.

I hope this guide is helpful, will be updating the guide so please let me know if I should change/add stuff into this guide :)

In my video, I can show you the fastest and easiest way to get this achievement.
I believe that it could take you around 1 hour to complete.
Just make sure you have the room in your bank.


Thanks
Killarpong

This might seem fairly obvious to some but If you don't care about the loot, the most guns per hour isn't completing the match.

Simply grab your starting chest,
Sprint to the nearest extraction point,
Open it by hitting
Then just mash to throw them in,
Die,
Repeat.

You can maybe get 2 if they're close by, but you'll learn which are easy before the half way point.