Hmm... after looking closely at some pics, youre right, on full auto, the bolt might touch the selector abit. Either way, 13cm sounds good to me!
Heres a very nice picture album that might come in handly if you are interested in making a proper replica. Although these are pics of various different AKs, it will give you the general idea of somethings.
http://www.imagestation.com/album/pi...?id=4288324981
Oop, there we go:
http://www.bsg-dornier.de/schiessen/...alashnikov.mpg
Look at that, the handle almost gets upto the selector bump, on some shots its upto a cm away, due to slight variations in gas pressure. I guess the bolt doesnt need to travel the entire distance to cycle reliably.
Can you make it eject realsteel shells while youre at it? And somehow fit 30 shells, 30 bbs, and a nice big gastank inside a 30round magazine? Just kiddin
Keep us updated!
Cheers!
Alex