I don't personally own a Mauser SR, but I can tell you from my experience with bolt action airsoft rifles that you do not need to upgrade anything other than what you mentioned.
-The trigger resistance might affect accuracy if it is a really heavy pull......but it will not make that much of a difference.
-The cylinder might be a concern if there is a huge variance in FPS from shot to shot (which would obviously affect consistent BB placement at long range).
-And a bi-pod doesn't make that much of a difference either.......unless you are very shaky to begin with.
A tight bore barrel and an after market hop up unit (if a quality one is available) will make the biggest difference. Followed possibly by barrel spacers.
But remember that regardless what you do to it that it can only get so accurate......after all, it is only airsoft. LOL
Last edited by Sha Do; May 7th, 2012 at 22:13..