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.
TAC-50 Mag.dat
GUID 17622d787e3a47ce943317484ef1899c
Type Magazine
Rarity Rare
ID 58893
Size_X 1
Size_Y 1
Size_Z 0.3
Amount 5
Count_Min 2
Count_Max 5
Calibers 1
Caliber_0 56130
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_Supply_0_Critical
Blueprint_2_Build 55048
// TAC-50 mag
Blueprint_3_Type Ammo
Blueprint_3_Supplies 1
Blueprint_3_Supply_0_ID 58893
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