here is the link to complete The Boot Camp in Vanguard  Thanks Snap for helping out on this.
https://www.gfinityesports.com/call-of-duty-vanguard/boot-camp-challenges-how-to-complete-rewards/
 
COD Vanguard Boot Camp Challenges
1. Get a Triple Kill without dying (x20)
2. Get a kill after swapping between primary and secondary weapons (x10)
3. Win a Match (x5)
4. Get a Kill with a Mounted Weapon (x5)
5. Get a Headshot (x50)
6. Get a Kill while Crouching (x10)

Vanguard Tactician Challenges and Rewards
1. Get 3 blind fire kills
2. Run through 5 walls
3. Get 20 kills after reloading
4. Get 10 mounted headshots
5. Get 5 mounted multi-kills
6. Complete all tactician challenges Reward: 10,000 XP

  I Hope this helps everyone out

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Still don't know what a blind fire kill is or how to achieve that challenge.

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Throw a grenade of some kind where you can’t see a target. I did it on the Pacific map and on Deciy over the building but any map has places to throw just keep chucking…

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Actually I found this video. How I got it to work is when you come up to a corner or a wall, you will see the two lines to mount your gun. If you pause and press fire instead of mounting, you will blind fire around or over the wall. It doesn't always work and not all corners or walls will work.

https://www.youtube.com/watch?v=W6bnC1Lr7qE&ab_channel=SkullBusters

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