How does a cylindrical magazine work?

Question

Like the magazine on the pp 19 bizon.

Answer 1

can you explain a bit more. Thanx

Answer 2

Cylindrical magazines (better termed helical magazines) are, as I'm sure you're aware, variants of drum magazines.  They are much more complicated however, and given the difficulty of engineering them, manufacturers are unwilling to put detailed specs on the web for anyone to copy.  In fact, I suspect most are so proprietary that they can't be found on the web in a readily accessible form.  If I were going to go sleuthing for this (which I'm not), I would start googling terms like "helical magazine details" or "helical magazine design" or something like that.  But I would be fully prepared to have to take some time to go far down into the search results because there will be a lot of frivolous hits and a lot of relevant hits without the details you really want.  

You also might want to ask this on usenet in one of the weapons-related newsgroups like alt.guns or rec.guns  I suspect that somebody there knows in exquisite detail how they work.