These guns are insanely blocky and, well, not very realistic in any immediate respects. The grips are literally rectangles.... Try different styles and get really creative. One that I'd like to be seen remade is the last, green one.
Try using curves and instead of fully black outlines, use a color a few shades lower than what's inside.
Along with that, try looking at guns and seeing how things are placed. Try to make some creative laser guns, but add some realism, just my recommendation.
The concepts you have right now aren't, honestly, too good, but I think you can improve. Good luck.
. Also try and think of some names for it since i cant think of any. Just imagine having one of these in your hands but a better version of it, I still work on the designs if you want me to add a bit more. 
