Gundrills, Reamers, Rifling Buttons, and Toolpost Holder for: 556NATO (223 remington), and 762NATO (308 Winchester)

grabcad

Gundrills, Reamers, Rifling Buttons, and Toolpost Holder for: 556NATO (223 remington), and 762NATO (308 Winchester).In making the barrel; Heattreat the blank to 27-32 HRC, gundrill, than ream with the rough reamer, than the finishing reamer, turn the outside diameter of the blank to get a true to boore outside diameter, than button rifle, than stress relief the barrel again to 27-32 HRC. You now can profile the barrel how you want on the outside without ruining the rifling and boore dimensions. I did a lot of research on the correct sizes of the parts. The thickness of the gundrill shanks however, the only reference i have got is from the modern gunsmith file: "(.281-.218)/2=.0315 thick walls, or .0315*25.4= .8001mm thick." Use the picture of the mcmaster catalog to get an idea what kind of steel tubes are around, from these sizes you should make your pick (there are more sizes around, keep that in mind). The reamers are the newest addition to my uploads, these do need some explanation: The reamers need unevenly spaced flutes because otherwise they will cause chatter! Chatter is a very destructive phenomenon that will destroy gundrills and reamers alike. Division on the flutes in degrees:4 fluted reamer 1st 0 2nd 88.1538 3rd 180.9231 4th 268.61546 fluted reamer 1st 0 2nd 59.0769 3rd 121.1538 4th 178.8462 5th 241.3846 6th 298.8462The right fluid pressure, right angles on the tools when making/resharpening, and feed rate, are essential in keeping these tools from catastrophically failing and destroying the barrel and the tools itself (that is the worst case scenario). See the ReportGundrilling file for examples. Figures on the oil pump? If you run up to .50 CAL, 7 gallons per minute, pressure 525 psi, 2.5 hp. With smaller calibers the psi rating goes up and the hp and gpm goes down. 700psi/4gpm/2hp 30 cal, 1000psi/2gpm/1.5hp for 22 cal. Other sources: 700psi for drilling, 200psi for reaming. You want a low volume high hydraulic pressure pump with at least 1000psi force. Get a 1.5hp low volume high pressure hydraulic pump and it should be fine..... I added some books by Harold Hoffman that go into detail on making barrels and tools. I also added some pictures of home made toolpost grinders (some of the easiest ones looked like wood routers in a frame). If you want to make gundrills, reamers and buttons yourself, it is essential that you have this tool for your lathe. A lathe with a spindle bore no less than 1.5" is e...