Mini-Bunkers are mid to late game POIs that offer unique challenges, and rewards. Some items can only be found inside of these bunkers, like Military Electronics, and Mechanics Tools
To enter a bunker, you will need a Bunker Key. These keys are only consistently found in Convoy Cases, with a chance to get 1-5 each time you open a case.
There are three different types of bunkers, lets just call them easy, medium, and hard for the purposes of this wiki. There is only one easy bunker on the map, located south of Krasnoe. This bunker doesn't spawn any turrets, or any melt-open crates, just a few random tech and gear spawns. Medium level bunkers can be spotted by looking at their entrance. If the concrete walls are gray, its a medium level bunker. These only have two rooms, they spawn a few turrets, melt-open crates, and sometimes endgame weapons and gear. Compared to the hard bunkers, they can possibly drop similar ground spawns, and are much faster to clear. However, hard bunkers are where you are going to get the most loot. These can be spotted by the camo pattern concrete entrances. Each hard bunker has three rooms, connected by long hallways and stairs. The first room usually won't have much loot, but will have some turrets and traps to deal with. The two rooms at the bottom are where you are going to get some solid loot spawns, and a few melt-open crates.
If you are trying to clear any medium or hard level bunker, you should come prepared. These bunkers will spawn dangerous turrets that require specific gear to effectively fight. Before you even step into a bunker of this level, consider preparing some of the following gear:
Depending on the difficulty of the bunker you are trying to attempt, prepare more supplies. Medium level bunkers can spawn up to 6 turrets, and hard bunkers can spawn up to 12 turrets! Although this will vary depending on which specific bunker you attempt.
You will encounter both types of turrets, some mounted on tripods, some mounted on the ceiling. Walk through the bunker slowly and carefully, expect a turret to be around any corner. In some bunkers, ceiling turrets can be placed directly above a door, shooting you as you walk through.
The turrets on tripods are much easier to deal with, two well placed grenades can quickly remove them. The ceiling turrets are more of a problem, as they are more difficult to hit with a grenade. This is where the M99 and GRM-40 really shine. Using an M99, get close to cover, quickly lean with Q or E, and pop a shot into the ceiling turret before it can shoot you. This will take practice to get down, so expect to get hit by the turret a few times. The same strategy can apply to the GRM-40, except that you don't always need to expose yourself to the turret, use splash damage by sending a grenade into a nearby wall.
At all times in the mini-bunker, watch for tripwires. The world designers at Bad Pixel clearly had fun with the tripwire placement, some of them are very sneaky. Pay extra attention when stepping through doors, walking through corners, or going down stairs. Thankfully these traps are easy to deal with, just back up and send a round into the grenade to detonate the trap.
Using these strategies and the right gear, you can clear out any bunker on the map. If you play on a PvP server, don't forget that you are making a lot of noise, especially when detonating those grenade traps. Anyone within render distance (400M) will hear them go off. If you use Dynamite, the sound of that explosion will travel 3km. Mini-bunkers are extremely easy to camp, since there is just one entrance and exit. Consider saving a few smoke grenades or explosive grenades to assist your exfil from the bunker. If you have a teammate, it may be a good idea to have them sit outside the bunker as a lookout while you clear.
Once you have dealt with all of the traps and turrets, its time to reap the rewards! There will be lots of loot scattered across the bunker, everything from explosives, fabric, scopes, even high tier snipers and ARs. But you probably came here for the melt-open crates Once you find one, equip your transport repair kit stack from your hotbar, and hold G to melt the crate. It may take multiple tries, and multiple repair kits to open a single crate. Inside you will find tons of Medicaments, Military Electronics, Mechanics Tools, Cameras, and sometimes laptops.
Here is a map with all mini-bunker locations clearly marked. While most mini-bunkers have a POI dot on the map, not all of them do.
The one easy level bunker south of Stepnoe is marked in green.
Medium level bunkers are marked in orange.
Hard level bunkers are marked in red.