High XP server config

Hi all, I plan on hosting a high XP server but im currently having some issues with the proper commands to make the high xp work. Currently i have tried scr_xpscale 4 and get xpscale is read only. I have also tried adding this to the config:
//TDM based xp points
set scr_tdm_score_kill "500"
set scr_tdm_score_headshot "500"
set scr_tdm_score_assist_75 "80"
set scr_tdm_score_assist_50 "60"
set scr_tdm_score_assist_25 "40"
set scr_tdm_score_assist "2"
set scr_tdm_score_suicide "0"
set scr_tdm_score_teamkill "0"
set scr_tdm_score_dogkill "3"
set scr_tdm_score_dogassist "1"
set scr_tdm_score_challenge "250"
set scr_xpscale "5"

Neither of those have worked, if anyone could help me out that would be awesome, thanks!