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

Last crawled date: 1 year, 11 months ago

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 268.6154
6 fluted reamer 1st 0
2nd 59.0769
3rd 121.1538
4th 178.8462
5th 241.3846
6th 298.8462

The 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 essential for drilling barrels for the button rifling method. Up to 50 bmg barrels can be made with this. I have seen some table top models that can do this. You also need a vertical milling machine to make the reamers. But basically you want a milling machine that is big enough to mill your receiver or pistol part, and also has room for a dividing head to make your barrel making tools in.

I also have added a toolpost holder for the gundrill, and reamer.

The reamers, buttons, and adapters are inductions brazed onto each other. As can be seen in some of the pictures and videos. Also the video shows a gundrill shank being heated by induction, formed and heat treated at the same time. Very interesting to see induction again, just as we saw in the bullet factory upload. I am still looking for a book that has all the answers about induction in it. So i can design my own induction apparatus.

I added 2 more books, one about metal working, and another one about welding. Check out page 260 of the welding book, and page 230, and 313 of the machining book. Check page 833 of the Machinery handbook. Check jigs and fixtures for ideas on how to build them for holding your tools and parts for machining.

It is best to read and make both the welding and the machining book, an keep all the other books i give you a read. Keep the Machining book for reference when you try to build something.

Next upload: Probably the 6.5 creemoor, 300 blackout, 300 HAM'R, and 22TCM.. Or maybe the heattreatment oven module 15 amp 230 volt, 3 modules.. I guess we will see...

Please press the like button when downloading!

For now the upload is a bit of a mess, i will clean this up tomorrow. Some shanks and other parts files/ assemblies got uploaded.




NOTES:
223 Remington Barrel (.219 bore, .224 groove)

-Barrel blank 1.125"-1.250" diameter (drilled and reamed before turning outside diameter)
-HRC (rockwell C) 27-32 HRC
-Drill .213"
-Gundrill shank .198" OD, .152" ID (This may be to thin (!!!) so: .120" ID if it f*cks up)

-Reamer 1 .217"
-Reamer 2 (bore dia.) .2195"
-Land on reamer 1/64"
-Rake angle reamer 5 degree
-Relief angle reamer 13 degree
-Flutes 6
-Flute width .044
-Reamer rod .202" OD, .120" ID

-Button rifler/reamer .2278/.2202"
-Button pull rod .208"


308 Winchester Barrel (.300 bore, .308 groove)

-Barrel blank 1.125"-1.250" diameter (drilled and reamed before turning)
-HRC (rockwell C) 27-32 HRC
-Drill .294"
-Gundrill shank .281" OD, .218" ID (or 7mm (.276") OD and 5mm (.197") ID)

-Reamer 1 .298"
-Reamer 2 .3005"
-Land on reamer 15/704"
-Rake angle reamer 5 degree
-Relief angle reamer 13 degree
-Flutes 6
-Flute width .060
-Reamer rod .277" OD

-Button rifler/reamer .3132"/.3012"
-Button pull rod .290"

Button rifle and then stress relief to 27-32 HRC, it makes the bore and rifling spring back to SAAMI specification. (.219 boore and .224 rifling, and .300 boore, and .308 rifling, for 556NATO and 762NATO accordingly)