Some solid advice there gingerbreadman and sitting duck. This was the reply i received:
"I only respond to the dispute as my money has been taken out of the account which is no good. I did not respond on the forums due to not having time as I have told you. I did not manage to read the messages? If anything the battery may have shorted the gearbox or something along the diagnostic path. One defence is from a boy I let borrow it one game day saying it was working fine however when the battery ran out began to misfire. Other from my friend who was shooting it in the garden 'target practicing' both full saying it had been working. If you wish to buy another fuse or send to myself for repairs I will repair for free."
To put it into context, I asked him why he never replied to me on the forum; i sent him three messages between the 26th and the 29th of August and according to the site, he viewed each message (although he says otherwise) which obviously got me worried that he was a scammer, so I started a dispute in paypal on the 2nd and he replied straight away which seemed off to me as he only cared about the deal when his money was in danger. Obviously now he has two 'witnesses' and has given me a more friendly option; if i post the gun to him, he'll repair it. For me there are two problems with this, firstly it being that i don't trust him: i couldn't trust him to tell me that he wasn't going to send a battery with the gun, and I couldn't trust him with his explanation of the problem (that being that the battery shorted the motor, which everyone has now debunked) despite him being a self-proclaimed 'tech'. Because of this I don't really want to post him the gun because if he holds on to it and waits for the dispute to expire, I'm screwed. Likewise I don't really trust his defences (how hard is it to ask a mate to lie for you and say that a gun works) or him saying that he never viewed the messages, simply because he doesn't seem like a trustworthy or reliable person. The other problem is that I don't want to have to pay (postage or parts) to fix a problem that shouldn't exist and that I didn't cause. He's still adamant that I caused the gun to break which pisses me off slightly because I'm pretty sure I didn't. Also just an fyi, he said he posted the gun on the 29th of July, but the package was damaged (this is when the battery broke) and the gun arrived on the 26th of August. He never gave me the tracking details so I don't know much about it, but it seems like a suspiciously long time not to tell me about the battery, and it also means that his witnesses/defences refer to the gun quite a while before it was actually posted to me (the postage that resulted in me actually getting the gun).
Thanks for all of the responses so far and any more comments are appreciated, I am thinking about making the dispute into a claim so paypal decides what happens, but I certainly don't want to rush into anything. Thanks guys. And any thoughts on who paypal would side with?