Spring guns like high-friction barrels, for the most part. Nested barrels work best in air guns, and to an extent in spring guns such as the Crossbow and Max Shot. The idea is that you want to be able to have the pressure from the air being compressed between the moving plunger head and the dart to be behind the dart for as long as possible without reducing efficiency. Otherwise, you have a shorter range with a lot of wasted air pressure. With a high-friction (a.k.a. "tight") barrel, this pressure has a longer time to build up before the dart will begin to move, and that's a good thing.
You could nest the barrels for anything, but I doubt it would help in this kind of case. If it does, post the increase in performance.
Edited by SHADOW HUNTER ALPHA, 31 August 2007 - 11:54 PM.
The only commonly shared fate among us all is death. I turn to the shadows so that I may not be unfamiliar with hell's corridors when I arrive. - SHADOW HUNTER ALPHA
Founder of the Shadow Militia.
Founder of Nightshade Laboratories and The Nightshade Armament Corporation.