I do recall some guy had a bad pour (did not fill in the Herschel style tiger stripes) and he melted the bad pour off the stock in kitchen oven and set the stock on fire... Ended up running around in the kitchen in a robe and flip flops trying to blow out the flames. Second try worked out fine... After he deepend said stripes...
Wood burns at about the temp the pewter melts. Heating a stock in the oven over 150 degrees is REALLY not recommended. Shrinkage is a pretty good bet.
Best to melt the metal away with a hot copper or brass punch heated with a torch. I use the same to solder up flaws if not too extensive. BUT its possible to scorch the wood with the punch unless careful.
The second pour usually pours much better since the wood is dryer and there are fewer bubbles and such.
Its always best to heat the barrel till too hot to touch where the pour will contact it since the barrel is heat sink that will suck the heat out of the melt and ruin the pour.
Heating the wood in the pour area with a hair drier or more carefully with a heat gun is also advised.
Dan