I also did this mod because unless you've modded the barrel to be air tight with the firing barrel you're gonna loose distance.
i appologise for the lack of descriptive photos, but it's a reasonably simple idea an im sure you can figure out anything i've been vague on.
you'll need the following:
a CS-6 stock
the attachable flick up sight (i got mine from the cs6)
NOTE: please see additional photo if you're confused about the last two items.
Step 1: Lets Do This! Cutting This Bad Boy Short
wow this is hard, i hope you're still following with me.
Step 2: Relocating the Cocking Mechanism
the next part is a little hard to describe, so i hope you can more or less guess what i've done...
have a look at the addititional photo ive provided. basically i just cut and used a section of the peice. maybe if you look at the other picture you can see what part ive used... to be honest, you could use anything to do the same job... this was just the first thing i found that i thought might work.
anyway, if you worked it out, you can superglue it in i guess, just make sure if you screw it in, trim the screws that will no doubt go through the bottom, cos your clip has to fit in there....
Step 3: Last Part!
Attaching it to the gun (gun is assembled at this point):
ok so on the bottom of the sight there is the clip, and a raised bump... cut out the bump so there's a small rectangle hole... i then used fire and heated up around the rectangle, then i pushed the heated rectangle slot over the piece on the gun which was protruding. now it's molded on but can still be removed if needed.... tada! you should now be finished...
again so sorry for poor descriptions....