Your "space gun" is a hell of a lot better than their blowback semis with plastic bodies that look like machine guns lol. You don't need to change anything, play paintball and be happy. A rail isn't going to do anything for you accept cost you money.
ETEK 3LT, with 14" Ti boomstick and cure 3 + bolt F/S
Vanguard creed eyes, membrane, bolt pin, detents, gaskets, schraders, orings and more F/s[/color]
Old school angel poppets/cup seals(LCD and A4/speed), spring detents(not sure which models) F/S