I am sure someone has tried. What would you like to have for power. 20 fpe enough?
All you need sells on Ebay by Cobalt327. He sells the power springs that he has special made and larger air delivery tubes that have a larger ID. I have them in a new Red Rider and older ones. The Red Rider in stock form only gets about 270fps in spite of advertising claims. Mine get about 100fps more after installing the parts. One gets 390fps. The High Road mentioned above has all you need to know about how to go about it. They are way more fun at that power level. Rip right through steel soup cans not just aluminum soda cans without bouncing back at safe distance. Of course this strong spring makes the gun a bit harder to cock.
What great fun!I have the cobalt kit, been watching for a clear horizontal surface to install it.How is the 499 barrel grafted in? Thank You.