I got this wonderful and detailed pistol crossbow plan to share. It's a very workable design, BUT it may very well hurt someone if not used properly. There are at least 50-60lbs draw weight in the recurve bow of this crossbow by design. So... if any injuries and/or damages resulting from this crossbow design, i will not take any responsibility for providing the plans.
Right Click at the picture and Save As on the pictures to download.
This plan and instructions for this crossbow is credited to Science and Mechanic Magazine and its authors.