I've used the Carl Gustav 84mm quite a bit (since each infantry platoon in the Danish army had at least three of them). For a while I trained gunners on it, and have fired it a lot, including the fused canister anti-personnel rounds and aweseo illumination rounds, in addition to the "regular" AT rocket rounds. The regular AT round can penetrate a lot, and we expected it to be effective against pretty much any soviet tank up to and including the T-72 (except for bad frontal shots on sloped armor, obviously)
In the late 1980s there was also an enlarged AT round available. It loaded a charge in the back (lilke the normal rounds), and then a larger war-head in the front. It could penetrate 900 mm of homogenous steel armour, which could handle anything in the Soviet arsenal at the time, even frontal (I believe). However, I never actually fired one of the enlarged warheads, so I'm certainly no expert.