If the rifle does not have a liner, the vent hole will have to be larger.
With a WL liner, which runs about .052"(seems to me) , I usually open it to 1/16" (.062").
Once that burns out to over .077", it's time for a new liner, unless you are using very coarse powder.
The larger the hole, the more of your fine(3F) powder gets blasted out the vent hole as you push the ball down
the bore. At over .070" that could be considerable)
This variable loss of powder simply adds to the shot to shot velocity variation as the amount lost is not consistent.
Consistency is very important for accuracy.