Thanks guys, I really appreciate all this feedback, really such a huge collection of knowledge.
Realistically speaking, after reading the review on the STAR M4A1 I'm not too interested in it. I'm think I'm a little more inclined to liking the King Arms M4 a little better, as suggested by wildcard (pending further reading though). I understand it has a working bolt catch but I couldn't find any videos where they actually fire it.. does the bolt lock back when the bb's stop feeding? The reason I ask is because the only reason I want a working bolt catch is so that I know definitively when to reload and so that the gun does not fire when there are no more rounds, for the sake of realism I suppose.
Secondly, does anyone know/is able to describe to me/is able to direct me to somewhere that analyzes in depth how bolt catch systems work in some airsoft guns? I'm curious to know if it's got to do with how the gearbox is arranged or..??? Goes without saying it's pretty tough to visualize or imagine what it looks like or how it works without having an actual gun
but yes, thanks again for all your help guys.