I can see myself becoming quite a regular Topic starter for the next month or so. Not in vain however, and once its all sorted and I'm up and running I'll pipe down a bit.
So, to todays question. The R85 Piston problem. I am aware they are renowned for stripping pistons even with the blowback disabled (Which it is)
Therefore, I believe (And this is where the question, confirmation comes in), I need the Piston spacer shown below.
http://www.airsoftworld.net/piston-spacer-for-army-arma