Bore Tech Proof Positive Patch Jag, 375 Calorie Precision Machined to strict tolerances in order to work flawlessly and provide true, concentric pressure on the barrel surface Eliminate the annoying false indication of Copper fouling that is common with all traditional brass jags when using Copper removing cleaners Each Jag length is specifically determined based on the caliber and proper patch size necessary for Cleaning Features A Reverse Taper At The Rear Of The Jag That Provides A Completely Smooth, Edge Free Transition Between The Jag And Rod When Used With OurProof-Positive Bore StixCleaning Rods