How do you screw on the PDI cylinder head for the VSR-10, L96, M24, etc ?
 

It looks like it might need a special tool because of that angled cut on the face of the cylinder head. I know Laylax makes a special wrench to tighten their own Laylax cylinderheads for bolt action rifles, but their wrenches won't fit PDI cylinder heads. Additionally, I already asked PDI (directly on their Xfire website) if they sell a tool to tighten their cylinder heads, but I didn't receive a response.

http://www.x-fire.org/vsr10/img_cyli..._vc/e.head.jpg

I used a bench vise set at the right width to use it as a wrench. Screw the cylinder head by hand, then gently tighten the final 1/4 turn with the help of the wise.

here, take this:
http://static.howstuffworks.com/gif/wrench-1.jpg

^-- +1

or a Vise

I use a cloth tho so i dont get teeth marks on my cylinder heads