I've played this dangerous game in the past and more often than not, lose. One of my favorite parts of the Bowyer's Bible mention's (in regards to rushing and hogging a lot of wood off with power tools; '...immediately stop and go stick your head in a bucket of water...'. I remind myself of that everytime I start getting excited or rushed and make the deliberate, hard decision to step away from my work. I find that when I don't listen to that message, I lose a lot of valuable time and work... My suggestion in this case would be to keep your bow in the hot box until you get to the moisture content you're looking for and don't rush it. Using a heat gun to hasten the process could weaken the wood unnecessarily and you're just asking for trouble (thicker sections will have a higher moisture content as compared to the thinner sections). Cheers, P1.