Buy a sniper even a modest priced one will be better overall
a pistol is a pistol
a sniper is - well a sniper
& a G36c is - well you get the picture
not saying you can't turn G36c into a DMR though usually the longer barrel models
heck you can I suppose fit a 455/510 barrel onto a mp5k I guess
Even if you did convert it to a DMR "some" sites get a bit picky as to what they will allow
nope that is just a long M4 and not a proper DMR - they could say
but it is locked to semi and longer barrel & higher fps - it is a DMR ain't it ????
don't care it is just a long barrel M4 and not a proper DMR
(yup some sites can be a little picky or uptight on "DMR's" I have heard)
Also - you could convert it all good & proper, then find out it is too boring waiting around back at MED
then wish you still had your G36c to get stuck in up the front
your gun is good all rounder except maybe on the longer range battles.....
So keep it as is, then get a reasonable modest bolt action sniper to do what it is supposed to do
well that is my take on it but many people think their next upgrade path will be either DMR or insane ROF
where as most will use say a couple of guns for different situations
horses for courses as they say.