The BG20 (Blitzgewehr 20; Lightning Rifle, .20 Cal) is an advanced PDW designed by Phoenix Precision Firearms' German division.
The BG-20 was concieved when PPF's previous SMG/PDW, the 10mm PPF Thunder, proved inefficient against body armor (even with its special +P armor-piercing rounds), and was deemed too uncomfortable for a PDW, but a tad too big for a machine pistol. Therefore, Daniel Phoenix instructed his German colleagues (a couple of which came from H&K) to design an all-new PDW. The result was the Blitzgewehr: a direct-impingement firearm firing high-energy .20 caliber rounds from a 11" barrel at nearly 4000 m/s. The team put a lot of effort into designing the new round. Several months later, the M18 THOR platform was created, and the then-prototype BG20 was modified to fit into such a body. The first units were shipped to the GSG-9 and the Heer in 2017. It now serves in many countries where the P90 was used before, effectively phasing it out and severely harming FN Herstal.
As mentioned before, the BG20 fires a unique round: the .20 KGP (Kurz Gewehrpatrone; 5x33mm), which is, in essence, a shortened 5.56 with a thinner, shorter 5mm bullet. It fires a 28-grain bullet at 4,000 fps to reach a muzzle energy of 1000 feet-pounds. This round (in an AP configuration) has the capability to pierce a CRISAT target at 400 meters and a full level III plate at 100 meters. This round was devised for several reasons, one of them being the optimisation of short weapons with barrels that are too short to accomodate the 5.56 properly, and also to fit in pistol grips should the need arise. The BG itself sports a collapsible stock (and a rather unusual one, too: when the stock is collapsed, the extra length rests INSIDE the gun), four rails and a choice of 3 magazines: 20- or 30-round double-stacked and 50-round quad-stacked. It has 3 firing modes: semi, auto and burst (trigger group: SEDF). Being extremely lightweight and portable, as well as undoubtedly the most powerful SMG-size PDW, it is a very valuable asset. It also has the THOR rear receiver, allowing it to be remade into a different weapon easily. The gas block is adjustable, allowing for three different rate of fire settings.
It should be mentioned that the BG20 has around the same efficiency and accuracy as a CQBR (10.5" barrel) M4, and thus sometimes feels more like a carbine than a PDW. Nevertheless, it has been compared countless times to the MP5, and exceeded it in every way.
Name : BG20
Weight : 2.1 kg (with empty mag)
Length : 25" (unfolded), 21.5" (Folded)
Barrel Length : 8.5"
Magazine Size : 20/30/50 rounds
Caliber : .20 KGP
Muzzle Velocity : 1200 m/s
Optimal Range : 2-200 meters
Effective Range : 400 meters
Rate of Fire : 750/1000/1250 RPM
Name : .20 Kurz Gewehrparone
Bullet diameter: 5 mm (.19 in")
Shoulder Diameter: 9 mm
Base and Rim diameter: 9.6 mm
Case length: 33 mm
Overall length: 43 mm
Rifling Twist: 1 in 9" (229 mm)
Standard loads: 28 gr steel-core bullet @ 1200 m/s; 45 gr spoon-tip bullet @ 950 m/s