Here is what you will get out of this mod

1) By putting the spring behind the hammer it make it ezer to push the hammer down the gun. This is because it stops the little binding that would happen when pushing the bolt and dragging the big hammer.
2) The mag spring is short so it does not keep pressure on the hammer at all time so this makes it ezer for the gun to recock.
3) Then there is speed! The gun will get one maybe two b.p.s. faster
4) The gun will also be a little better on gas. This is because it is ezer to recock the hammer.