That's bolt on parts not mods, I'm talking non standard stuffGranted there are a lot of mods available for Tippmann, mostly off the shelf... .
That's usually harder than people realize mainly because the only markers that will really fit inside a nerf frame are more expensiveTrbo323, that is absolutely gorgeous. I'm more the guy, though, that prefers the simplest internals possible. And you're right, I should've made the distinction between bolt ons and mods. I'm cheap. And stupid. I would seriously strip out a Nerf gun and put a marker inside.