I just completed a bunch of testing using various ammo and magazine combinations. The only other type of ammo I had access to was
Valken 0.25s non-bio. The
BB Bastard Frag ammo seems to be problematic from what I can tell, and my King Arms mid caps seem to be the worst performers. I'm kind of upset because the sales rep (at Hero's) who sold them to me implied they were the same as the regular BB Bastard ammo, which they clearly are not. I definitely won't be buying Bastards any more, there wasn't a scenario I could come up with where there wasn't at least a minor problem)
Also, my MAG brand magazines don't seem to sit well in my magwell. After about 5 shots the magazine's spring trys to push more BB's into the hop-up, but instead pushes itself down and out of the magwell about 1/4" which prevents and more BB's from feeding.
Here is a chart I made that summarizes my findings.
Red is the worst, with no feeding possible in all but the most forced scenarios.
Green is no problems, or what I would consider perfect, light-green is "usable" but with minor problems. Yellow is frustrating and inconsistent feeding.
Some magazines have #s which correspond to a labelling system I have on these mags to keep track of which ones I'm using in-game.