hi . I have bought frame brackets that will accommodate a 4x6 and 4x4's for a swing set. The hardware for the 'swing platform" and the "swurfer" which are different than swings but look fun will be attached with lag screws into the 4x6 top beam. I think the 12 foot 4x4's that are the legs should be attached to the frame bracket with bolts that goal the way through the 4x4's and the 4 inch side of the top 4x6 lumber. any tricks to getting a straight hole through the wood so that I can put a bolt all the way through? I hope this makes sense. Basically I'm asking how to drill a straight hole through 4 inches of PT lumber.