fps..

On most maps if i leave my fps uncapped i get 300+ fps always unstable ofc but its always over 270fps no matter where i go..

my problem is this.. when i cap it at 125 its unstable always dropping to 124.8 117.3 etc.. and only rarely do i see 125.0 on my fps counter

my vid card isnt the best but im sure its capable of holding 125fps stable or is the problem related to other things.. r_displayrefresh ? monitor hz? etc..

please could someone give me some advice so i can stable it out thanks <3