Warren Cleaning Jags are machined .040 smaller than caliber size to provide the snug fit of .020 cleaning patches. Extra long stem prevents patch hang-up. Jags are spherically cupped to center rod over ball when used to load. A major difference is that the base of the Jag is .020 over-sized in order to stop the muzzle guide from wedging under the patch. The stem is set with an 8 x 32 or 10 x 32 steel stud.