BLoodSirehitscan: cl_interp .033
Projectile: cl_interp .0152 or 0
Medic: same as Projectile
sniper: .314159265359
Also note that the lower the interp is, the quicker you will see projectiles. That is a crude way of saying it, but useful, as you may wish to play with 0 interp on scout, for instance, in order to dodge better (maybe).
Are you serious about that sniper interp? :(