I'm not sure about the SR25 and G3 since I never own any of them but what I can suggest for the SCAR is VFC SCAR-L or H.
I have an SCAR-L, it shots right out of the box even it's plastic bushing and clear piston, but still I put almost 15 k in there and still no issue. I would upgrade it when it's break and plus I want to know how this gun last long in stock form.
My VFC SCAR-L doesn't need much maintenance. There are only a few that I usually do after each game.
-Clean the inner barrel.
-Lub some silicone oil on hop up rubber, not to let it try
-Cleaning the external of the gun,
Like I mention, I don't upgrade any internal yet of the gun but it's performance out of the box, still I did a few
-I bought 3 kind of tight bore which 300 mm for CQB, 363 mm for Outdoor game, 509 mm for being marksman because I have 3 different kind of outer barrel.
-Put a new G&P hop up rubber to get more accuracy.
Just only those two upgrade this gun is shot far beyond a few upgrade gun on the field in their internal stock form.
Last edited by KND; March 18th, 2009 at 18:05..