The Pr.191M was the upgraded, production version of the Pr.191. It featured new M-50 engines, making the boat slightly faster, addressing a key issue with the previous version. It was also equipped with new 14.5 mm KPV heavy machine guns, replacing the older 12.7 mm model. The boat entered production in 1947, although there were initial issues with the hull's bottom, which were later resolved. A total of 188 Pr.191M units were produced between 1947 and 1954, with most being assigned to the river patrol fleet.

Introduced during Update 1.79 "Project X" alongside the initial Soviet fleet, the Pr.191M retains the same crew count and armour layout as the previous version but has a faster speed. The boat still uses the 85 mm cannon but now comes equipped with a 14.5 mm KPV heavy machine gun that can penetrate up to 40 mm of armour at close range, making it effective at destroying enemy boats and some more armoured targets. It also has magnetic mines, though they are not particularly effective at sinking enemy destroyers.