7.62x51mm, roller-delayed blowback, belt-fed from a 150-round box. Highly accurate and with serious damage output even at long ranges, this is the king of LMGs. Gun specific mods include an even longer barrel, a short tactical foregrip, and an ergo grip.
The Brenner 21 Light Machine Gun is the last weapon made available, having a reputation lock of 75.
The Brenner suffers from a very slow reload time, even for a light machine gun. Ammunition is fed from a detachable box magazine, allowing for tactical reloads which take 5.4 seconds to complete, and an empty chamber reload takes 6.4 seconds.
The Brenner has the highest standard damage, a good rate of fire and, for an LMG, impeccable hip fire accuracy. This, combined with its large 150 round magazine and useful mods can make the Brenner 21 an extremely powerful weapon to use on heists where trouble is expected and one would need to cover a given area from enemies. This comes into play especially in hallways, as its good range allows it to take down anything that comes in front of it.
It also has the second highest capacity of all the LMGs and a good total ammo, meaning the user is safe from ammo shortages for quite a while, unless it is actively used in a full on assault, and even then one would need to be very careless with their ammo expenditure. In bad situations, an Enforcer with the Bullet Storm skill can activate the skill with the placement of an ammo bag, granting up to 15 seconds of continuous fire without ammo consumption, and during that time one could easily chop down an entire wave of police attempting to approach the player. The Brenner 21's sheer damage also makes it great against Bulldozers, being able to cut one down without much of a problem.
While the Brenner 21 is the most accurate out of all the LMGs, it still suffers from inaccuracy at long ranges. While using it one should always stand still unless absolutely necessary and zoom in the view. Mounting mods, such as the Long Barrel and the Tactical Laser Module can make the Brenner 21 even more impressive, as they boost its versatility greatly.
*The LED Combo is based on the Leapers, Inc. UTG LED Weapon light and Laser. **Although the main flashlight has a toggle switch, the laser sight component of the LED Combo is pressure-activated, meaning the laser will stay on as long as the pressure switch is depressed. This switch is not placed where it should be, however (on foregrips, magazine wells, etc...) and is instead ziptied to the main taclight, leaving no plausible mean for the user to toggle it without awkwardly moving their off hand off the weapon and gripping the attachment itself.
The Brenner 21 is based on the Heckler & Koch HK21E that has been modified with a proprietary feeding channel to facilitate the direct use of ammo belt boxes for quicker reloads. The in-game Brenner 21 sports a classic MP5-style diopter drum rear sight instead of the adjustable one usually found on the Export models.
Being based on the HK21E, the Brenner 21's fire selection dial features a 3-round burst mode, though the in-game weapon is restricted to automatic fire and single shots only.
Alongside the Buzzsaw 42, the real-life Brenner is considered a general-purpose machine gun, and not a light-machine gun. This is because of the 7.62x51mm NATO full-power rounds it fires classifying it as such.
"Brenner" is the rough German equivalent of "Blowtorch", while "Patronen für Handfeuerwaffen" on the ammo box means "Cartridges for Small Arms".
The HK21E is incapable of receiving pistol grip modifications in reality, as do a large number of G3-pattern firearms due to the grip being an integral part with the weapon's lower receiver and trigger group. The closest it can get to an actual grip change is to either swap out the entire lower receiver block with one that has a customized grip, or use a grip sleeve.