I guess it’s from all of the years of reloading and bench shooting that I find 30rd magazines to be annoying to shoot from the bench with.  I consider myself to be a pretty good shot, but you do have to learn how to get into different shooting positions if you really want to get good with a rifle.  I stared out shooting SKS rifles and could get 3-4 inch groups on a good day, but when I tried shooting groups with an AK, I felt like a was standing on a unicycle.   Sometimes having higher capacity magazines means more bulk and drag.

I’ve had my share of owning 75rd drum magazines, but the amount of work that goes into loading those really takes away the fun of shooting them.  It’s kind of like when you were a kid sledding down a big hill, after the 2nd or 3rd time you were so worn out from walking up when the ride down only took 20 seconds.  The gun magazines are magpul pmags in my opinion and I would even consider picking up 10rd pmags for DMR work or bench shooting and 20rd mags for fighting.   I don’t think there is a difference in reliability with any of the various magazine capacities, but getting down on the ground and putting accurate shots on paper with a 30rd can become awkward.  There are positions you can try, but they aren’t for anyone not in good shape.