Ebon Hand said:
That isn't true Bean, the Assualt Cannon has to hit before it gets a chance to rend. Statistically only two or three shots hit, then those shots that hit need 6s to get the rending effect. Also, like monkey king said, they only have 24 inch range. With a landpeeder's movement, that comes to 36, but it puts the landspeeder in harms way, as opposed to safely blasting it from behind cover with a troop.
Sure it can try to do anti tank with assualt cannons for a turn if you need it desperately, or if you have lots of them, but saying that it beats Lascannons as an anti tank weapon is wrong. I have tried it and it just isn't reliable.
Actually, it is true. Did you even bother to do the math?
Lascannon against armour 13: 2/3 (to hit) x 1/2 (to get a result) or a 1/3 chance to get a result from a single shot.
Assault Cannon against armour 13 (one shot): 2/3 X 1/6 (one you've rolled a six against the armour, a result is guaranteed) or 1/9 to get a result. That makes the chance over four shots of getting at least one result 1-(8/9)^4 or around .38 (38%) 38% is higher than 1/3 (which is about 33%).
In addition, the chances of the result from the Assault cannon being a Penetrating hit are
much higher than the chances of the result from the Lascannon being a penetrating hit. In addition, while the lascannon can only get one result--and is less likely to get even that one than the assault cannon is to get at least one, the assault cannon
can get more than one (even though it's unlikely). It only goes more in the assault cannon's favour when you go up to armour 14.
Do the math next time before you 'correct' things that don't need correcting

.
That being said, the Range does reduce its effectiveness somewhat--but still, at a range at which both have shots (which isn't hard for most of the ass. cannon toting units to achieve) the ass. cannon performs better against high-armour vehicles than the lascannon.
Also, for referrence, the Assault cannon is definitely a common anti-tank choice. It isn't replacing lascannons in tac squads or devastator squads, but that's only because
those units can't take them. I use Assault cannons almost exclusively for anti-tank in my lists, and they're great.