Yes they will, however not all mid caps can be sawed short on that part because some have longer springs there.
http://www.youtube.com/watch?v=murNRHKBF1Y
Here they show it on King Arms magazine(I also did it on my own KA mags), and as far as I know MAG magazines are good too. Real Sword mags require no modding. If you hit the mags a bit harder in the magwell before sawing them you will see a little mark where they get stuck, which could help in sawing the right amount.
Well the look pretty similar to EMAGs from what I can see. I have EMAGs and they don't fit in my F2000 for the sam