Here's how I drill the handle. I start off by marking where I want the split-nuts, then I use a forestner bit to drill for washer or bolt, the first side will use the forestner. Then I drill the hole for the bolt using the pilot from the forestner bit, and finally use the forestner bit on the other side.
So, you always wanted to build handsaws...
Slotting Fixture
Slotting Back
Stamping Teeth
Making a Handle
Assembling the Saw