This item is not included in any spawn asset, but it doesn't necessarily mean that it doesn't spawn naturally on any of the maps.
AMS.dat
GUID 53313681b7074551a1787894524067aa
Type Magazine
Rarity Mythical
ID 52471
Size_X 2
Size_Y 2
Size_Z 0.1
Amount 5
Count_Min 1
Count_Max 5
Calibers 1
Caliber_0 51020
Tracer 51000
Blueprints 1
Blueprint_0_Type Ammo
Blueprint_0_Supplies 1
Blueprint_0_Supply_0_ID 52471
Blueprint_0_Build 30
Delete_Empty
Spread 0.75
Recoil_X 1.1
Recoil_Y 1.1
Ballistic_Damage_Multiplier 0.9
Ballistic_Drop 0.8