To be honest I'm not an airsoft guy I'm more paintball do I don't know a lot about the interior of an airsoft rifle. I took it to where I bought it (Heroes Army Surplus in Oshawa) and got their airsoft tech to put the gearbox back together. The new spring that came with it was longer than the stock spring and what he told me was that this will decreases the velocity of the rifle and won't hurt the gearbox thus preventing my gun from being "destroyed". I hope this info was helpful
