308 to 30-06 chambering question
- Thread starter Polinese
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dakota.potts
New member
Clark, that picture kind of hurts to look at. Would like to see the results. It is a very clean cut for a saw.
That saw is a Black and Decker hand held bandsaw with a SWAG mount so it is not handheld. I made an H shaped cross cut jig. I am getting too old to use a hack saw for an hour to cut through 5 square inches of steel.
I used that barrel stub to locate a pin hole in the receiver.
I just cut the shoulder on a Pac Nor Stainless Super Match. 1-8" Twist. 6mm. Polygonal rifling 28" long Factory Remington Mountain Rifle Contour barrel. .... until that Holland recoil slipped on at 1.063".
I'll cut threads in the morning.
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Polinese,
I was looking through QuickLOAD's database and found a fellow named Dave Kiff came up with a .308 Ackley Improved design. It adds about 3 grains of case water capacity to the cartridge, so if it were formed from one of the lighter .308 cases, you'd get within about 7 or 8 grains of the capacity of a typical .30-06 case, and with the more efficient case shape, pretty much eliminates the .30-06 velocity advantage with bullets up to 180 grains. I compared the two with the high velocity producing Reloader 17 with a 180 grain MatchKing in the software, and a typical .30-06 case (about 69 grains case water capacity) at maximum SAAMI MAP (60,000 psi) gave a 24" .30-06 barrel a velocity of 2892 fps, and the Kiff .308 AI formed from a light .308 case (62 grains water capacity) a compressed (104.4%) load velocity of 2879 fps from that same powder at the .308 SAAMI MAP (62,000 psi).
It looks like the design is probably the same as the JGS 308 AI 40, as both have shoulders with 40° half angles (80° included angles). JGS would therefore have reamers. CH4D sells the dies for the JGS version. This design would clean your chamber and let you use the same short action, if that's what you have. Like all AI designs, you just fire the parent cartridge (308 Win) in it to get formed cases, so that part's easy, too.
I was looking through QuickLOAD's database and found a fellow named Dave Kiff came up with a .308 Ackley Improved design. It adds about 3 grains of case water capacity to the cartridge, so if it were formed from one of the lighter .308 cases, you'd get within about 7 or 8 grains of the capacity of a typical .30-06 case, and with the more efficient case shape, pretty much eliminates the .30-06 velocity advantage with bullets up to 180 grains. I compared the two with the high velocity producing Reloader 17 with a 180 grain MatchKing in the software, and a typical .30-06 case (about 69 grains case water capacity) at maximum SAAMI MAP (60,000 psi) gave a 24" .30-06 barrel a velocity of 2892 fps, and the Kiff .308 AI formed from a light .308 case (62 grains water capacity) a compressed (104.4%) load velocity of 2879 fps from that same powder at the .308 SAAMI MAP (62,000 psi).
It looks like the design is probably the same as the JGS 308 AI 40, as both have shoulders with 40° half angles (80° included angles). JGS would therefore have reamers. CH4D sells the dies for the JGS version. This design would clean your chamber and let you use the same short action, if that's what you have. Like all AI designs, you just fire the parent cartridge (308 Win) in it to get formed cases, so that part's easy, too.
Dave Kiff designed the reamer I am about to use.
I told him the neck size and the bullet.
Custom reamers are good, but can take too long to deliver, from him or Manson.
I cut threads this morning:
https://www.youtube.com/watch?v=PDmE31ERfx0
now chamber
I told him the neck size and the bullet.
Custom reamers are good, but can take too long to deliver, from him or Manson.
I cut threads this morning:
https://www.youtube.com/watch?v=PDmE31ERfx0
now chamber