Question about the CFX roller breech

[RedFeather]

I'm trying to get a good idea of what the tap (roller) looks like. I have a CFX, but I'm not ready to pull it apart. Seen a picture of a BSA tap (original CFX design) and see the flat barrel side with the small, offset transfer port and o-ring, and see there is a large outer ring on the back. What does the rear of the tap look like? Is it simply flat like the front but with no o-ring (just a hole)? Is there a gap or bit of space between the rear of the tap and the face of the compression chamber or does it bear against it, aligning the hole in the tap with the compression tube's transfer port? Just can't find any fore/aft pictures.

Thanks in advance!

[cfxdragon]

There is a link to the parts diagram for the CFX in the library in the top left section. IIRC when I had mine apart there was no transfer port per say but rather the rotary breach is the transfer port. The seal of the piston lands right at the rear of the rotary breach. The large o-ring at the rear of the rotary breech is what acts as the front seal for the compression chamber as the rear end of the rotary breech is the front wall of the compression chamber. When you remove the spring and then the piston the next thing to come out is the compression sleeve that the piston moves inside and then the breech. There is a seal around the front OD of the sleeve and the sleeve keeps the rotary breech from moving rearward. Reading CDT's how to on the seal replacement in the Library may also help explain it. I wish I had a pic I could post.

It has been a couple of years since I had mine apart but that is how I remember it. I am sure that if I am wrong someone will correct me.

[cfxdragon]

after thinking a bit more the sleeve might not need to come out to remove the breech.... but you get my point I hope.

[RedFeather]

Yeah, I get it now. That's why you can partially cock the gun and slide the tap to the rear in order to replace the barrel side ring. Lots of potential for leakage in that system. Thanks!