If you want to swap, you will have to pay in a lot!
Find a spare barrel and build a stumpie.
It reduces the overall length of the rifle to manageable proportions, and creates an incredibly easy-to-shoulder gun, (better than a bp configuration of which I am a huge fan) - at a fraction of the cost of buying a premium brand. My stumpie in 4.5 was the best gun I ever owned. I am sure it would work very well in 5mm.
Speak to Sinjin... he knows!
can help with that.Ratel Sporting Airguns
Forum name: UllUllA
Services: Manufacturer of RSA air rifles. Custom crafted stocks for all makes of air rifles