I agree the police were way under equipped but the AK type rifles were using large drums to hold big capacity of armor-piercing rounds and their caliber is high enough to penetrate car doors, which they knew.
First off, drums, magazines, etc. are not that much of an advantage. Capacity is what it is, shot placement is always critical, if you have 40 rounds or 100 rounds and cannot accomplish your goal of suppression or hitting on target you are simply wasting ammunition. Rate of fire is not the advantage people think it is, you lose accuracy and limit your options to "lucky shots". AK-47s are not "super weapons" they are semi-accurate, they do however have durability, but they fire what amounts to a small rifle round, it's a large .22 for the most part which is actually smaller than a typical large game hunting rifle. Where the danger comes in is the tumble effect of the round, not the power behind it considering most hunting rifles have a larger size and more powder loaded.
They weren't that dug in if you saw the video of the fire fight, they were right out in the open a lot wearing 40lbs of body armor, ducking behind vehicles off and on. It took ankle level shots to drop one and a wrist/hand shot on the other who shot himself after that. Also they had taken phenobarbital to calm their nerves before the robbery. So I wouldn't say it wasn't the weapons but it was a combination of will and preparation.
If they were able to hold position they were "dug in", that comes from tactical prep. this is not a cheap shot at the police, considering they had to go on the best information available. Basically these clowns had the will to cause damage and the arms choice was a secondary consideration. Like TD stated, they were stopped using common hunting rifles, if the AKs were "super weapons" that would not have been a possibility.
