With AP/API like the A10 mostly fires (5:1 API:HE), Unless a round is fired at a perfect 90* angle to the ground, there is a chance it will deflect and bounce, all the videos posted show this quite well, 7.62mm/20mm/23mm/30mm/105mm/120mm doesn't matter, as long as we're talking about a solid projectile (not HE/HEI) there is a chance it will deflect/bounce, this is pure elementary physics, think of it like skipping a stone on water, water is mass and dirt is mass, it is possible to skip anything off a body of mass with the right velocity and the right angle.
Now this is a game we're talking about, and a mid-fidelity sim at that, we aren't going to see perfect physics, the system in the game is very good under the circumstances, yes it seems goofy at first because this is the first time in a sim (besides DCS:BS) that we have really seen it. But it IS pretty realistic, whether you like it or not. Now whether the A10 in the game should be firing tracers is up for debate, but for the purposes of a mid-fidelity sim, I like the effect of the tracers, and I think it adds something to firing the gun.
The reason the A10 has such a high-rate of fire is to put a ton of lead (DU) on target every time the trigger is pulled. This is done because 1 or 2 or 10 rounds may not penetrate fully, may miss or may bounce. You put 100rds on target, say 10-20% bounce, 30% don't fully penetrate, 30% miss slightly, 20-30% hit the target AND fully penetrate hopefully hitting something vital and igniting a fire/explosion.
To the guy above me who can't kill a tank with the Avenger in FC2. I just set up a training mission for myself with some T72's, T80's, and a T55. The Avenger rips through them all with a solid accurate 100-150rd burst on target. It takes a few seconds for the target to explode after being hit. I have noticed (may or may not be accurate, but in my experience...) that it helps to engage the big MBTs from a steep dive so that your ammo hits the top of the turrent/top of the hull where the armor is weakest. From a shallow dive/angle it takes over twice as much ammo to kill one.
I start from about 4000ft and enter a fairly steep dive, hit the brakes and kill the throttle, zoom in and put a solid 150rd stream on the target to ensure a kill. It can be difficult but remember, when aiming, be smooth and deliberate, knee jerk movements wont work so well.
/first post here, hope it's helpful
Chris