of deburring cone 22 the outer blades 24 move back and forth along arrow f thereby changing the point at which they intersect cone 42 of deburring cone 22 for purposes of utilizing deburring cone 22 with deburring tool 10 to deburr a cartridge shell 29 as shown a positioning tool 25 is provided which consists of a base 26 with an extension 27 attached thereto extension 27 has a point 28 positioned thereon so that as extension 27 is pushed inside of cartridge shell 29 and positioned properly it will extend through the igniting hole 51 of cartridge shell 29 deburring cone 22 rod 20 and positioning tool 25 are all substantially concentrically located on axis h so that they turn on axis h fig2 of the drawings is an expanded sectional view utilizing a cutaway view of cone 42 of deburring cone 22 together with a cross sectional view of cartridge shell 29 and base 26 of positioning tool 25 deburring cone 22 has slots 35 into which blades 24 fit while only one slot 35 is shown in the cutaway of fig2 such slots are provided for each of the outer blades 24 the method of capturing outer blades 24 in slots 35 is shown in fig2 b of the drawings outer blades 24 also have slots 36 cut therein so that if outer blades 24 are positioned in slots 35 of deburring cone.