G3 DMR Project

[tobyeason]

Hi guys so im pretty new to modifying the internals on my guns but i thought i'd give it a go. My goal is to turn my stock TM G3 into a 400 to 425fps DMR and i have no idea how to do it. I know there have been threads about this on other forums and such but im just looking for some simple advise.
So for the minimal price what can i buy to get the best range and accuracy for my money?
Lets say a top budget of £80 i already have a Scope and Mosfet for it but thats all.

Any help would be appreciated