What is the benefit of proper feeding of the 1.75 inch shells if the shells are ineffective for defensive purposes? Before we proceeded with the the final design of the OPSol Mini-Clip, we conducted tests with quarter-inch plywood. We moved on to phone books and ultimately to bare FBI ballistic gel. After talking with Clear Ballistics, a leader in the ballistic gel industry, we decided to test their FBI ballistic Joe Fit Torso. At the FBI ballistic protocol distance of 10 feet from tip of barrel to target, shot one each, birdshot, buckshot, and slug, at different areas of the gel torso.