I use the term infantry heavy weapons to describe weapons that require a crew to operate but are light enough to be carried around by infantry without needing special towing or transport vehicles. Heavy machineguns, mortars and smaller recoilless rifles. As light crew-served weapons they will be located alongside other two-man infantry teams and be relatively freely available.
The M2HB .50 cal and 12.7mm Dshk are heavy machineguns mounted on tall tripods that serve dual purpose as light anti-aircraft and infantry support weapons. They are great at providing supporting fire but their crew is left rather exposed manning the machinegun.
The 82-BM-37 and M29 are 82mm and 81mm medium or 'infantry' mortars light enough to be carried by two men and provide long-range fire support out of line-of-sight, making them useful in built up and hilly areas. In HOTmod their range is actually on par with vanilla artillery, to give you an idea. Their relatively small shells are slightly more deadly than a grenade explosion, but without the warning.
Light Recoilless Rifles
The 73mm SPG-9 and 75mm M20 are light recoilless rifles deployed on small mounts and serve similar functions to WW2-era light anti-tank guns, but far more portable. Despite this, shoulder-launched weapons like the RPG-7 and M67 are almost on par with their armor penetrating abilities, but being mounted on sturdy tripods give these light weapons greater range and accuracy than the standard anti-tank soldier.
Light Anti-Tank Guided Missiles (ATGM)
In the late 50s and early 60s many nations developed a wave of small, man-portable ATGMs like the 9M14 Malyutka (AT-3 Sagger), French ENTAC and British Vigilant - except the United States, which primarily used the ENTAC (and SS.10/11) mounted on the M151 jeep (or helicopters). The Soviet Malyutka is the same missile mounted on the BMP, launched from a small suitcase launcher and crewed by two operators like the other heavy infantry weapons. Standard Soviet doctrine was for the ATGM assistant to be armed with an RPG to cover the 500m minimum range deadzone.
That's all for this blog. Next up, some light AA guns!