I have a P 3 (Heng Long) which I am busy collecting upgrade bits for and mods etc... one I am stuck on is the barrel, it has a metal short barrel currently installed, now I've totally stripped the turret and barrel assembly but for the life of me cannot get the barrel out, I know you get screw in versions as well, so I've tried screwing, pulling, pushing (think you get the message

How do I get it out?
Also the version I would like to try aim for is the ausf L with the L60 length gun barrel, so second question where can I get one from? I've had a look on interweb and resource articles but not getting anywhere on that front. Was even thinking of the panzer iv barrel, but the muzzle break on the end wont suit the build, unless someone can say that Panzers did have muzzles on the barrel ends?
any ideas welcome.
Thanks
Andy