The Operation 4: Brothers in Arms Title update for Gears 5 has 24 achievements worth 340 gamerscore.
Complete a Versus match on Reactor, Blood Drive & Checkout
Complete a Featured Horde Map from Operation 4
Complete all Year One Escape Hives
Escape a Hive with Paduk
Win a Match of Horde Frenzy (any difficulty)
Acquire any Weapon from the Fabricator in Escape
Escape all Operation 4 Hives on Experienced Difficulty or Higher
Wake-up in the Med bay while escaping a Hive in Escape
Complete 12 consecutive waves of Horde Frenzy with Baird & Paduk in your Squad
Win a Match of Horde Frenzy on Master Difficulty
Master All Featured Horde Maps from Operation 4
Deal 30,000,000 damage in Versus
Deal 100,000,000 damage in Versus
Kill 25,000 enemies in Versus
Kill 100,000 enemies in Versus
Get 12,500 assists in Versus
Get 50,000 assists in Versus
Re-up 40 Times
Reach Character Level 15 with 10 Characters
Win a match of Gridiron with an Operation 4 Hero or Villain
Kill an enemy using a planted Grenade in Gridiron mode
Get a Denial on an Enemy while they are inside your Endzone with the flag in Gridiron Mode
Master an Escape Hive and Horde Map from Operation 4
Unlock a reward in any Competitive playlist