Most medium tanks take two, sometimes more or less depending on where you stick them. With the stuff that typically takes one, like the pz.II, you're better off just using the Boys rifle really, and against heavier tanks like Tigers they're pretty much useless.
Is the Geballte actually more powerful than the stikkbomb? It seems to take mediums out sometimes in one shot (at most two), heavies (Matilda/Val) in two as well (one is usually enough to light one afire!).
I image what would happen to AT Rifles if somehow they got Upgraded, they can destroy even PzIVs and Shermans lets say.
They can already destroy a Grant
And with some luck, Pz3 and Crusader
The thing I like about AT rifles is how you can still kill inf, and scare tanks. The AT rifle is like a WTF rifle, its awesome against inf.
They are also VERY useful in taking down AT and AA guns. Two shots (against an undamaged gun; one against one with less than half HP) and they're gone - often from a distance from which they cannot return fire effectively. I like to play an engineer as well and I can tell you that nothing is more FFFUUUUUstrating than repairing an AT gun, then manning it, only to be killed seconds later by an AT rifle you cannot even see.
And yes, they are a good alternative to a sniper rifle - with practically zero bullet drop all the way to the "fog" distance they are very good in taking down non-moving soldiers, and with
a bit lots of practice, even moving soldiers...
And they are a light vehicle killer supreme as well.
Ladies and gentlemen, I think we have discovered a new concept: AT RIFLE BIAS.