270-08?
01-14-2005, 02:10 AM
#2
Join Date: May 2004
Location: SW Virginia
Posts: 776
RE: 270-08?
The only question that comes to my mind is, WHY? Why would you want to go to all the
trouble/expense to build a custom rifle that would use a 308 cartridge casing necked down to take 270 bullets? I mean, to each his own, and it would be different, but we
already have the 7mm-08. The difference between 270 and 7mm is only .007".
You would likely end up shooting the same bullet weights as does a 270Win. or 7mm-08,
but would just be the tiniest bit smaller in diameter (.277" vs. .284").
trouble/expense to build a custom rifle that would use a 308 cartridge casing necked down to take 270 bullets? I mean, to each his own, and it would be different, but we
already have the 7mm-08. The difference between 270 and 7mm is only .007".
You would likely end up shooting the same bullet weights as does a 270Win. or 7mm-08,
but would just be the tiniest bit smaller in diameter (.277" vs. .284").
01-14-2005, 02:22 AM
#3
Join Date: Jan 2005
Location: Rocky Top Tennessee
Posts: 683
RE: 270-08?
The legendary P, O, Ackley asked the same question when confronted with the .263 Express, a precursor to the .260 Remington, by Ken Waters. He was of the opinion that you'd get better veolcity due to the larger bullet diameter. History as shown however that velocity isn't what the .260 is about, and why give up what the .270 Winchester already provides. So the question is once again, why bother?
01-15-2005, 07:26 PM
#4
Join Date: Mar 2004
Posts: 74
RE: 270-08?
Actually PO Ackley likes it very well. There are 3 very similar choices to look at for a wildcat short action 270.
A 270 Savage - Which is a 300 Savage necked down to 270 Bore.
270/257 - A 257 Roberts necked up, or 7x57 necked down.
270/308 - Necked down 308.
If you would like a short action 270, these are just about all you can build from, unless one of the new offerrings from Win or Rem cover it. However all the new Magnum's are pretty severely over bore, so maybe I should say the above options are the only ones in an efficient cartridge that will allow longer barrel life.
I would suggest straightening out the walls, similar to an Improved cartridge, when the barrel is chambered so you can gain that advantage as well.
From PO Ackley Vol 1
.270/.308 "This is a very fine efficient .270 cartridge made by simply necking the common .308 Winchester case to .270. It resembles the .270 Savage, but being slightly larger, it provides somewhat higher velocities, and these velocities compare very favorably with the standard .270 Winchester, and a multitude of the larger .270 cartridges, including the Magnums. The .308 necked to 7mm is quite similar to the .270 version, but it handles the heavier bullets at very satisfactory velocities."
.270/.257 Improved (Ackley) "The cartridge is the Ackley Improved .257 necked up, or the Improved 7x57 necked down to accept the .270 bullet. The same can be done with any of the other versions of these two cartridges, with similar results. Like the .270 Savage, this case is of lesser capacity than the standard .270 Winchester thus producing a more efficient cartridge. The standard .270 Winchester is somewhat over bore capacity and not as efficient as slightly smaller cases. Actually, the .270/.257 Improved produces velocities fully as good as the standard .270 with slightly less powder. It is a cartridge which can be highly reccommended for all types of American game."
In the data, the .270/.308 and .270/.257 are very close. 130 Grain bullet 3030 to 3130 fps, 4831 and 4350 powders listed.
The only downside I can see is that the chamberings being discussed are true wildcats instead of improved chamberings. So some time sizing brass would be involved. But that's OK, we need something to do on these cold nights anyway.
The 250/3000 Improved is on my wish list for a custom gun.
A 270 Savage - Which is a 300 Savage necked down to 270 Bore.
270/257 - A 257 Roberts necked up, or 7x57 necked down.
270/308 - Necked down 308.
If you would like a short action 270, these are just about all you can build from, unless one of the new offerrings from Win or Rem cover it. However all the new Magnum's are pretty severely over bore, so maybe I should say the above options are the only ones in an efficient cartridge that will allow longer barrel life.
I would suggest straightening out the walls, similar to an Improved cartridge, when the barrel is chambered so you can gain that advantage as well.
From PO Ackley Vol 1
.270/.308 "This is a very fine efficient .270 cartridge made by simply necking the common .308 Winchester case to .270. It resembles the .270 Savage, but being slightly larger, it provides somewhat higher velocities, and these velocities compare very favorably with the standard .270 Winchester, and a multitude of the larger .270 cartridges, including the Magnums. The .308 necked to 7mm is quite similar to the .270 version, but it handles the heavier bullets at very satisfactory velocities."
.270/.257 Improved (Ackley) "The cartridge is the Ackley Improved .257 necked up, or the Improved 7x57 necked down to accept the .270 bullet. The same can be done with any of the other versions of these two cartridges, with similar results. Like the .270 Savage, this case is of lesser capacity than the standard .270 Winchester thus producing a more efficient cartridge. The standard .270 Winchester is somewhat over bore capacity and not as efficient as slightly smaller cases. Actually, the .270/.257 Improved produces velocities fully as good as the standard .270 with slightly less powder. It is a cartridge which can be highly reccommended for all types of American game."
In the data, the .270/.308 and .270/.257 are very close. 130 Grain bullet 3030 to 3130 fps, 4831 and 4350 powders listed.
The only downside I can see is that the chamberings being discussed are true wildcats instead of improved chamberings. So some time sizing brass would be involved. But that's OK, we need something to do on these cold nights anyway.
The 250/3000 Improved is on my wish list for a custom gun.
01-15-2005, 10:07 PM
#5
Nontypical Buck
Join Date: Jun 2004
Location: NW Ohio , 5 min from Ottawa National / Magee Marsh
Posts: 2,051
RE: 270-08?
Why do it ? Why shoot the same rnd as every one else ,to be different.
IMO chambering the rifle would be easy if you stick with the 270 porfile , just use a 270 reamer and not insert it all the way ( about 1/2").
For the dies you could take a standard set of 270 dies and machine off the right amount off the bottom of the die.
Or if Redding dose not allready make that die set they will for a price.
It would make a sweet Rem Model 7 chambering.
IMO chambering the rifle would be easy if you stick with the 270 porfile , just use a 270 reamer and not insert it all the way ( about 1/2").
For the dies you could take a standard set of 270 dies and machine off the right amount off the bottom of the die.
Or if Redding dose not allready make that die set they will for a price.
It would make a sweet Rem Model 7 chambering.
01-17-2005, 06:24 AM
#6
Nontypical Buck
Join Date: Jun 2004
Location: A flat lander lost in the mountains of Northern,AZ
Posts: 3,171
RE: 270-08?
how bout the 270 WSM kinda looks like a 308 necked down to 270. from what i hear its better ballistically then the 270 win and its also a short action caliber that alot of gun manufactures offer in their line of bolt actions. that would kill 3 birds with one stone 1. wouldnt have the hassle of spending a ton of money on a custom gun 2. its short action caliber 3. its 270 caliber just food for thought good luck
01-19-2005, 01:16 AM
#8
Boone & Crockett
Join Date: Feb 2003
Posts: 10,679
RE: 270-08?
Guys, if we all stuck with standard cartridges then we wouldn't have the 7mm-08, .243, .270 win, 338-06, 35 Whelen so on and so on.
If you can have a 30-06 then why do we need the .308?
I've often wondered why this is not a standard cartridge. Seems it would be a natyral bases on the .308 case just like it was with the 30-06 case. It's the only one missing.
The only downsides that would cause a person not to build one is the huge cost involved and time required to do it.
You couldn't use a standard .270 reamer because you would be cutting off the wrong end of the chamber. You need the back of the reamer rather than the front of the reamer. The .308 and 30-06 cases are identical except for the length.
You run into the same problem again.
If you can have a 30-06 then why do we need the .308?
I've often wondered why this is not a standard cartridge. Seems it would be a natyral bases on the .308 case just like it was with the 30-06 case. It's the only one missing.
The only downsides that would cause a person not to build one is the huge cost involved and time required to do it.
IMO chambering the rifle would be easy if you stick with the 270 porfile , just use a 270 reamer and not insert it all the way ( about 1/2").
For the dies you could take a standard set of 270 dies and machine off the right amount off the bottom of the die.
01-19-2005, 10:46 PM
#9
Join Date: Jan 2005
Location: Rocky Top Tennessee
Posts: 683
RE: 270-08?
I kinda think the .308 has a little more shoulder angle than the .30-06 or .270. I do understand what you said about the reamer though. Just send a .243 barrel to someone who does reboring. I'd be willing to bet that RCBS has the dies in stock. Although they'll come with a good deal of sticker shock!
01-20-2005, 12:10 AM
#10
Boone & Crockett
Join Date: Feb 2003
Posts: 10,679
RE: 270-08?
This rifle would be expensive enough with out reboring and recutting the rifleing in a barrel. Besides that you would still need to have a reamer for it as the throat, at a minimum, would still need to be cut and to cut it with a 270 reamer would likley cut it out of center due to the fact that the front of the reamer is signifigantly smaller than it would be on a short case. It would be completely unsupported except for the pilot inside the bore. Way to easy to tilt the reamer off parallel with the bore and possibly snap off the pilot.
A reamer should be less than $200 to purchase. I know you can rent a 270-08 Ackley for only $33.00 from Elk Ridge. Not sure what Clymer would charge to rent one. I'm sure they already would have one ground though as this is not a rare a wildcat.
A reamer should be less than $200 to purchase. I know you can rent a 270-08 Ackley for only $33.00 from Elk Ridge. Not sure what Clymer would charge to rent one. I'm sure they already would have one ground though as this is not a rare a wildcat.