The Haenel MP28/II was an German submachine gun that was designed by Hugo Schmeisser in 1928. It was an improved version of the World War I-era MP 18. The MP28/II differed from the MP18 in that it fed from straight box magazines, featured a fire selector, and used a wide diameter return spring rather than a guide rod.
Initially, the MP28/II was produced in Belgium to get around the Treaty of Versailles, which heavily restricted domestic production of small arms in Germany. After the Nazi Party got into power in 1933, the Treaty was disregarded and production of the MP28/II moved to the Haenel plant in Germany. The gun was never formally adopted by the Wehrmacht, but it saw use by German police and Waffen-SS units during World War II, and was also a successful export, seeing sales in Bolivia, Romania, Spain, and Portugal, among others. Production lasted from 1928 to 1940.
— In-game description
The weapon can be considered an alternative to the high rate of fire submachine guns of the Suomi KP/-31 and M1928A1, considering its moderate to high rate of 670 RPM. It improves upon these weapons with a larger standard magazine of 30 rounds, which is only slightly below the categorical standard 32 rounds, in addition to possessing low vertical recoil. However, the presence of stronger than average horizontal recoil makes the weapon somewhat unpredictable in automatic fire, while muzzle velocity is second lowest amongst the SMGs at 345 m/s, which cannot be modified via specializations. These factors befit a more close-quarters playstyle where its high damage potential can outpace slower-firing, more controllable SMGs.
As part of its specialization tree, the MP28 has access to Slings and Swivels, Polished Action, Extended Magazine and Enhanced Grips on the left side and Quick Aim, Custom Stock, Ported Barrel and Lightened Stock on the right side. Both routes offer improved accuracy while on the move and various handling improvements. With Extended Magazine, capacity is increased from 30 to 50 rounds with no corresponding reduction in reload speed, unlike the Suomi and M1928A1. Ported Barrel reduces horizontal recoil to 0.250 left and 0.300 right.