A bit of a stove geek here...
sooo.... this really depends on your oven. Mine was made in 1951.... and it totally has a fix for this. If you pull off the knob, there may very well be an adjustment beneath. Caveat: this may or may not apply to you!
On mine, under the main knob, there is an adjustment. Under my main knob is a secondary readout (calibrated with temperatures). The secondary knob has locking screws. You can loosen them and twist it.
In my situation, you put a thermometer in the oven, set it at say... 350 degrees and let it come up to speed. Once it has settled down (flame or element goes off) check the thermometer. If it says 300, loosen the screws and set the secondary readout to 300. Tighten it down.
You might have to repeat a couple of times to fine tune.
knob:

knob removed:

Put the knob back on and ... done.