No problem, you can move forward.
The 315V is still well above our B+ which is at 225V.
If the colour code on the resistor is correct (violet, green, black, silver) then the resisor is correct within 1%. The typical ohmmeters are generally not very acurate for the extreme values (very small or very large). Also, it adds the resistance of the leads, and connections to the resistor value.