March/April 1983 - American Handgunner

Bonanza, of Faribault, Minnesota, hasincorporated into its Co-Ax press a seatingpost and primer cup assembly that accomplishesthe jpb simply. As pressure is exertedon the handle of the Co-Ax, the topof the cup stops against the head of thecartridge. Then, as the seating post movesthe primer into the pocket, the cup ismoved downward against light spring resistance,until it comes to a stop against ashoulder at the bottom of the post. At thispoint, the cup and post assembly is preventedfrom traveling further. However,since the post is .004 inch longer than thecup, each primer is seated to a positive,uniform depth. Variances in rim thicknessdo not affect this system, and neither doesthe amount of pressure you exert on thehandle of the press.BONANZA PRESSIt is impossible, under this type of mechanicalcontrol, to crush priming mixture,and the legs of the primer anvil will restfirmly against the bottom of the pocket,pressed lightly into the priming mixturefor consistent sensitizing. This primer seatingsystem also is featured on Bonanza'sModel 68 reloading press:Control of headspace, firing pin protrusionand striking force, along with otherfactors that influence uniformity ofprimerignition, are important ifaccuracy and dependabilityare to be achieved. It is,however, just as important for the handloaderto do his part by taking care that theprecision with which primers are manufacturedis not spoiled on the loading bench.We thank Dean R. Purdie of Bonanza,and his father, for providing research informationfor these notes. Manufacturers,as well as individual handloaders, are alwayswelcome to contribute to the knowledgewe share in this column with readers.You may have heard about how seatingprimers behind thin plastic-Saran Wrap,for example-will prevent small powderkernels from filtering through the flashhole ·into the primer. Although this practicewould at first appear satisfactory, it isnot generally a good idea. The seating ofaprimer involves a calculated amount ofinterferencebetween the body of the primercup and the wall of the pocket. This tightnessof fit is intended to prevent primerback-u p, which can be particularlytroublesome in revolvers. The use of anyplastic material between metal surfacesacts against frictional grip; therefore, thedoubtful advantage of using plastic aheadof primers is cancelled. If that's notenough, consider the thickness ofthe plastic(about .00075 inch)-and double it. Thiscould amount to enough additional stressto cause permanent enlargement of thepocket.Ifyou have handloading information,or any helpful comments to share, writeto me at Handloading, Box 222, (AH),Pinon Hills, ~CA 92372. ~AMERICAN HANDGUNNER . MARCH/APRIL 1983--4.dvantgge Grip Systemcompetition proven by MICKEY FOWLERto win Bianchi Cup IVThe same grip system used by Mickey Fowlerwin the Bianchi Cup Match is now available tothe serious competitor and features:* Significant recoil reduction* Improved shot to shot recovery* Quicker sight picture alignment* Thick tapered hand filling grips* Distributes recoil forces better* Promotes a more consistent grip* Built in magazine loading chuteComplete Advantage Grip System with checkeredWalnut Stocks, $40.00-Add $2.00 for First ClassPostage. Calif. residents add 6%, sales tax. Quantitydiscounts available. Dealer inquiries invited. Writefor additional information and mathematicalcalculations.'"GUNPARTS1 W ·~~ONCatalogThe mostcomprehensiveguide of its type!BUY RIGHT WITH.,FRANZITEThe 7lf.1 ounces of weight alone accounts for a 17% recoil reduction.The thicker tapered grips provide a secondary recoil reduction bydistributing recoil forces over a larger area. It works. It can beproven mathematically. But above all you can feel it when you shootit and you can see it. The external dimensions remain basically thesame. All your existing equipment can be used without anymodifications. A magazine loading chute is also incorporated intothe Advantage Grip System. and the right panel is milled to clear theambidexterous safety tang.Mickey said, " ... at the Bianchi Match I can't afford to give upa single point to equipment." How many points are you willingto give up before you try the Advantage Grip System?P.O. BOX 828. WHITTIER, CA 90608 (213) 695-4134World's largestsuPPlier 0'gun parts.NUMRICH ARMS, the world'slargest supplier of gun partsoffers new Catalog No. 10covering a 150 million partsinventory with informationnever before in print.U.S. PRICE $2.95FOREIGN $3.95TED BLOCKER'S HOLSTERS ARE THE CHOICE OF CHAMPIONSMickey Fowler wins 3rd straight Bianchi Cup and the man v I s man speedevent using Ted Blocker's 1.5.1. competition rig.I.S.1 CANNON SAFE TEAM MickeyFowler, Mike Dalton, Craig Giffordand Mike Fichman remain undefeatedin the Bianchi Cup TeamMatch using Blocker's I.S.1. CompetitionRig. These winning teammembers know and demand thevery best leather equipment available.Write for free brochure or seeadvertisement elsewhere in thisissue.Ted Blocker's Custom HolstersP.O. Box 821 Dept A.H. Rosemead, California 91770Most durable grips made, precision-fitted forforeign and domestic handguns. Conventional,Conversion, and Target styles. Fourlustrous colors, ~Ius Sta..shorn.Send $2 check or money orderfor illustrated 32-page catalog.O~ Please do not send cash.*~~\fl~ ~