You Can Hit X > Press Your Gamertag > Go To Find Player > Type JullianGG and hit file share > Game Types > Jullian's Skirmisher Guide.
Grind Out Those Kills...
And Your All Set.With My Set Up It Took 32 minutes
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Homunculus Fury Pointed out in the comments that, If you do this with other players, they
Don't get progress toward this achievement,
Only The Host Does.
"If You're playing alone You're Fine."
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If You want to set this up on your own...
A Good Way To Grind This Achievement Out Would Be To Utilize The Fire Fight Options.
Firstly.
Hit FireFight > Custom FireFight > Pick a Small Map > Pick FIREFIGHT.Then,
In the Options Menu Go To FireFight Settings > Wave Properties > Round 1 Wave Properties.Now
Switch Drop Ship To DISABLED for faster enemy Spawns.Then
Change Every Squad To "SKIRMISHERS"Rinse and Repeat for
ALL SQUADS &
ALL WAVES
Go Back Till You See Initial wave, Main Wave and Boss Wave and Set All The Squads To "SKIRMISHERS" again.
Once That's Set, Go Back Till You See, Round 1, 2, 3 & Bonus Round Wave Properties.... Then Once Again Set All Squads to "SKIRMISHERS".
As Far As
Skulls You Should Turn Them All Off to make Life Easier. (Except Grunt Birthday Party Of Course)
Customize Your Self As You See Fit.. However..
I 100% Recommend These Settings
In Spartan Settings Max Out Starting Lives, Extra Lives,
Go to Base Traits, Shields and Health, Change Damage Resistance To
"INVULNERABLE"In Weapons and Damage, Max Out Damage Modifier to 300%, Melee Modifier to 300%, Infinite Ammo Bottomless Clip, Ability Usage Unlimited.
The Rest Is Up To You Like I Said Earlier, Like Movement Speed, What Weapon You Want to Use, How far You Want Motion Tracker Range to be etc.
Pick Normal Difficulty or Higher and You will Grab This Achievement Once a Set Is Complete
You Can Click in on the Right stick to save your customization.
Shout Out To Samba For Making a Map as well in the comments