Response trigger issue

I purchased my Tippmann a5 from a friend and he only used it twice, i formally was a 98c owner. when i got the gun it had a new Flatline and also his response trigger which worked ok.... I went to the field and tried it out at the chrono, and immediately i pulled the trigger and got 2-3 shots halfway through... i noticed that the silver visible pin behind the trigger was actually making contact with the trigger if not really really close ,(obviously from the air) well it worked great all day. that night i went home to put the pen spring mod in and i opened the trigger and put it in then put it back together then next day i went to the field and the silver visible pin behind the trigger was only going HALFWAY now, i turned th valve and still only halfway, i played with it for more than 3 hours that day trying to figure it out. I took the whole gun apart, relubed, polished internals, put back together, still the same problem, ive tried everything i can think of, i even took the stock off and put the original end cap on.

Help me please I liked my rt very much.

Thanks,

Sean

forgot to say, i took that out. right now im ordering a new o ring kit cause i just opened it again and where the cylinder inside the grip is connecting to the valve inside the gun, the o ring has a MINOR minor minor scratch on it so im gonna replace it.

"piston o-ring" is the name of the part and i took it off, now that i look at it, that "scratch is a slice. its deep into the ring cause me to be able to bend a hunk of the ring off with my thumb nail.

However in case this is not the problem... any other suggestions