If you go to the eastern entrance of fort Zancudo and cross the bridge towards Route 68, move towards the 3 fighter jets monument, millitary vehicels like The Barracks, The barracks Semi and the millitary jeep will spawn on Route 68.
I have yet to see a tank, but could be rare.
You will be attacked by the millitary after stealing any of the wehicles.
The Barracks semi is awesome for police chases, it's fast, heavy and plows through everything.
- Kent_Paul_Jnr likes this