Here is quote about how to measure I think alot of people were confusing this when taken by itself it is much clearer.
reach him when thou dost step forth with thy blow or thrust, and thy foremost foote and hand must goe together, and which distance may be twelve foot with a rapier, or with a sword four foote ling, and yet thy best foote which should be the hindermost foot of a right handed ma, should bee mored fast and keepe his standing without moving an inch
my translation: step forward with your thrust with the front foot and hand together, and you can cover 12 feet with a rapier, or sword 4 feet in length, and yet your weighted foot which should be the left foot of a right handed man should be moored to the ground unmoving and keep him standing with out moving an inch.
I think the confusion was on the front foot and hand if i am right handed i would lunge landing on my right foot, and the 12 foot is measured from the rear foot to the tip of the four foot blade.
Jeff
My mistake for leaping to assumptions instead of more carefully rereading the text. 
Oh well, the experiements were fun and I learned that I can hit a target with a rapier from an even greater distance than I had previously thought. Hadn't realized I was already doing Swetnams 12 foot lunge on a regular basis as the firm footed lunge is a standard of Italian rapier though I should have since Swetnam is basicly Italian rapier that happens to be written in english since he was teaching in England.
