Actual RPG-7 ammunition:
(Standard effective range is roughly 500m)
PG-7V: 260mm of penetration, 83mm from 1962.
PG-7VM with 300mm of penetration and much increased accuracy, 70mm from 1969
PG-7VS with 400mm of penetration, 70mm from 1972/1973
PG-7VS1 with 360mm of penetration from 1975 (cheaper version of PG-7VS)
PG-7VL with 500mm of penetration, 93mm from 1977 (range reduced to 300m)
PG-7VR with 600mm of penetration after ERA, 600-700mm of penetration without ERA, from 1988, 65 and 105mm (range reduced to 200m)
With an AP of 14 for the RPG-7 and 17 for the RPG-7V, the weapons appear to be using the PG-7V and PG-7M or perhaps the PG-7M and the PG-7S1 ammunition respectively.
These rounds are from 1962 and 1969 or 1969 and 1975(?)
Category C is 1980.
There exist three more modern and effective rounds designed before then, which bizarely are not ingame.
Furthermore, some units like Morskay Pekhota '90 are still using a round from 1969 or a worse version of a better earlier round in 1990;
For reference, 400mm of penetration equates to 18 AP on infantry launchers. (This is what the Carl Gustav M2 penetrates with its M551 HEAT round.)
The 18 AP 400mm PG-7VS came out in 1972/1973. (the VS1 came out a few years later as a cheaper version, it would have 17 or 16 AP)
Therefore, one could argue that every single RPG-7 unit should have 16 AP at minimum.
Many, should have significantly more.
The PG-7VL came out in the later seventies to counter the NATO proliferation of modern MBTs, it used a large warhead which decreased the range to 300m (525m in game) but increased penetration to at least 500mm.
This would be 20-21 AP in game.
(it gets oddly compressed after 425mm which is 19 AP, and then 700mm (non tandem) which is 22 AP, switching from 25mm per AP as from 300mm at 14 AP -through 19 AP at 425mm to something else)
TL;DR: RPG-7s should all have more penetration.
Right now they're really mediocre, they could be better without warranting a price increase.