Threading an unthreaded barrel.
 

So, while simultaneously wanting to get engravings on my GR25, I was also curious about threading the outer barrel. As you can see from this picture..

http://www.uncompany.com/images/g&g-gr25_big.jpg

The barrel on the GR25 sniper version (as opposed to the SPR version) is unthreaded. Now, I need to measure the barrel to make sure it actually could be threaded to say 14mm, but what would be needed to do this? Obviously I could not do this myself, but who would be able to do this? Any advice would be helpful.

PS, the only reason I want to thread it rather than replacing the barrel is that AFAIK there are no aftermarket barrels for this AEG. The chamber block is different than that of a standard M4/M16 variant. Thanks in advance.

take it into a machine shop and someone there should be able to do it but beware, not only will it have to be 14mm, but you also have to make sure depth or width of the threads is proper for silencers or flash hiders.

I believe most airsoft silencer uses 14mm x 1mm. Be it as CW or CCW...

Yeah definitely. Would having something threaded that I wanted to use, or another barrel with the same threading I want, on hand make it easy for a shop to copy?

Yeah, they could just measure the threads on the other one.

Treading is ANSI M14x1mm

Be it left/right hand.

I would recommend -14 (left hand) because most options are left hand treadings.

Alternatively you could tap (with the correct tap from... cdn tire or tool store) the barrel, and get a double ended (male male) adapter.