How do i decide what diameter auger i need for tapping birch? It's just for me, not a commercial affair. Having said that, it would be nice some time to collect enough to make a bottle of syrup. Does a bigger hole equate with more sap? The one i was looking at is 16" in length and 3/8" in diameter. Will that do for my purposes do you think? Or should i go for one with a larger diameter? (I think the other one was about 12mm in diameter). Or, should i be thinking even larger in diameter?