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.
M82 Mag.dat
GUID f46efd546954bf71dec557d41c208a75
Type Magazine
Rarity Rare
ID 58223
Size_X 1
Size_Y 1
Size_Z 0.3
Amount 10
Count_Min 8
Count_Max 10
Calibers 1
Caliber_0 56039
Spread 1
Shake 1
Recoil_X 1.5
Recoil_Y 1.45
Equipable_Movement_Speed_Multiplier 0.995
Tracer 48
Explosion 55073
Explosive
Blueprints 5
// Belt
Blueprint_0_Type Ammo
Blueprint_0_Supplies 1
Blueprint_0_Supply_0_ID 58357
Blueprint_0_Build 55048
// 1 round
Blueprint_1_Type Ammo
Blueprint_1_Supplies 1
Blueprint_1_Supply_0_ID 59576
Blueprint_1_Build 55048
// M82 mag
Blueprint_2_Type Ammo
Blueprint_2_Supplies 1
Blueprint_2_Supply_0_ID 58223
Blueprint_2_Build 55048
// TAC-50 mag
Blueprint_3_Type Ammo
Blueprint_3_Supplies 1
Blueprint_3_Supply_0_ID 58893
Blueprint_3_Supply_0_Critical
Blueprint_3_Build 55048
// Hecate mag
Blueprint_4_Type Ammo
Blueprint_4_Supplies 1
Blueprint_4_Supply_0_ID 59479
Blueprint_4_Supply_0_Critical
Blueprint_4_Build 55048