Bulldog 6 at the Army Warehouses is a mission given to you by General Voronin to enter the freedom base and take their bulldog 6.
General Voronin, will send you to find the bulldog 6 grenade launcher, which is in their armory in the box on the top of the lockers directly ahead of you. The freedom base has many useful things. In the armory there are three Z-M LR-300s, one with a 40mm grenade launcher, one with a detachable SUSAT scope and a ' plain ' one. There are lockers with ammunition, and some first aid kits, and some Freedom armor. If you don't want to get bad reputation with the Freedom then you can use a chair to get over the guards head, and to get out (See Bulldog 6 for more details on ways to get it).
You can wait till the siren sounds , each time it sounds the guard will leave his post, he will also leave when the Duty company under the command of Colonel Skull attacks the Freedom base, during the Destroy the Duty company mission.