Where does this O-Ring go?

I've got my friend's Tippmann 98 Custom that he asked me to clean but I'm having some problems putting it back together. It's not a standard 98 Custom, it has two springs behind the rear bolt as you can see in the pic which makes me think it is a 98 Custom with ACT (Anti Chop Technology). 

Edited by dklax77 - 06 April 2011 at 1:52pm

the pic doesnt work but I think i know what you mean. Im pretty sure the black o ring goes around the middle/center spring by the bolt. If you are talking about the buffer o ring which i think you are. It's on the manual you posted here look at the end cap and right beside it is the buffer o ring.

ya man thats the buffer o ring

Edited by jordanpischke - 06 April 2011 at 1:58pm

alright thanks for the replys. that's what i originally thought it was but it just seemed out to have it loosly around the spring

yeah it looks the same as the Bravo One. I'm thinking they just sent two long springs instead of one long an one shorter one, cause when i tried to put it back together it was all bent over and fully compressed. The only thing i see that i missed was the new buffer ring they sent with ACT kit. It is a little smaller and thicker then the stack one that came out of it. Ill take it apart this weekend and put the one they sent in. Oh yeah was i suppose to mill out anything on the receiver? not sure if anyone answered that question.