ALL Kalashnikovs are afflicted with 'mag wobble' and "canted parts' to some extent.
Well, sort of.
I agree about the wobble part, the canted part is something else, even amongst SAR's and WASR's.
Every AK I own or have owned has had mag wobble. Its more of a mag issue than a gun issue, but it can also be a combination issue. Some mags wobble in some guns and not in others. Even with mags that seem to wobble excessively, I have yet to have a problem with them functioning properly.
I've never used the drums, as they never appealed to me. Just never saw the point to screwing up a good thing.
On a side note, one thing you rarely see addressed about the AK's, is the dreaded mag suck. It is possible to insert a mag and lock it in, and have the gun be inoperable. Not in the sense that it doesnt function, just that it doesnt function. The mag is not in properly and the rounds are to low for the bolt to strip them. The gun appears to be working, but it just clicks when you pull the trigger.
What happens is, if you dont get the front of the mag seated properly, you can still rock it back and lock it under the catch. The even worse part is, it wont come out without a fight, and usually requires you to hold the rifle by the barrel, place the butt on the ground and kick the mag out. This tends to be more of an issue if you load the rifle using your right hand (assuming a right handed shooter) while holding the rifle with your left.
When I first heard about it, I had never had it happen before. I actually had to try and make it happen, but that required switching hands to load the mags, which I dont normally do. When it did happen, it was a major PITA to get the mag out. I havent had it happen very often, and until I got my WASR, never had it happen while loading with my left hand. I have had it happen with two WASR's, mine and my sons. Its usually when trying to load the gun quickly. It doesnt seem to be a problem with my other AK's, just the WASR's, so I'm assuming the mag wells may have something to do with it.