re-chambering a .308 barrel - Page 2

scoobydoo6906 · February 15, 2011, 11:35 PM

aftermarket barrels run $300+ without the chamber cut. I can't see how
re-reaming a new chamber would be any more than cutting a new one into a new barrel. I think even with the new barrel you still would want to square everything up even the barrel. if everything ends up costing the same I would get a new barrel but I don't see that being the case

lefteyedom · February 17, 2011, 11:10 PM

Scooby,

I have a 26" barrel long action 308. There really is nothing that a 30/06 can do that this 308 can't. If you get a chance to chronograph loads from a 308 and load from a 30/06 you will fine very very little difference. The difference often goes towards the 308.

A heavy 308 is a sweat shooting rifle, with little felt recoil. The accuracy greatly increase ones confidence in the field.

If you feel that the 308 is not enough gun for your elk hunting needs then you may want to make the jump to a 300 Magnum class or larger. I have a 338 Win Mag for my Elk, Moose, Mastodon needs.

Build a long action long barrel 308 and try it. If you don't like it have it rechambered to 300 Winchester.

langenc · February 18, 2011, 02:36 PM

While reading the posts on p 1, it dawned on me-you cant fool mother nature-or mother gunsmith.

AI w/ several more grains of powder to gain 50 fps-not for me. I usually down load for max accuracy anyway.

**Unclenick** · February 18, 2011, 04:56 PM

Scooby,

Brownells used to send a list with their catalogs to dealers of suggested service prices. Back in the early 90's it was $40 to rechamber. Today it's probably $60-$80, but that's just labor. If Reamer rental is involved you'll have to add that.

You still have the issue of whether or not there is enough metal. If you have something beefy like a Shilen #7 contour barrel to start, you'll be fine because the thick portion goes forward of the receiver 4". But if you start with a light sporter one, like a #3, where the thick portion is only 2.5" long, you may not. That will have to be determined by the gunsmith. But I would think that in most instances there will be enough to go from .308 to .30-06 AI because you don't need to set the shoulder back or re-thread the barrel. If you went to regular .30-06, the added labor is unlikely to make it as worthwhile.

If you load the .30-06 and the .308 to their respective SAAMI maximums (60 kpsi vs 62 kpsi), you get about 100–150 fps more velocity out of the .30-06 from a 26" tube, depending on the bullet weight. Add another 50 fps for the AI format, and you should have a 200 fps advantage over the .308. It's not magnum but it's not nothing, either.

With commercial loads you often don't see that .308 and.30-06 difference because the latter is more likely to be underloaded out of liability concerns for old rifles. The velocities were much closer when both were constrained to using 4895, which the .308 handles more efficiently. But the '06 can actually handle a slower powder better than the .308, and that picks up its potential. You just can't count on using a slower powder in the Garand or other gas guns as readily.

Loading for yourself, you can work up reasonably to maximum performance for your weapon. If you work up based on brass pressure signs, you'll likely discover your gun is happy running .30-06 AI at the same pressure as .308, in which case another 25 fps will be picked up.

scoobydoo6906 · February 19, 2011, 05:08 AM

according to noslers website the difference in a 180 grain bullet is more like 300 fps.

dahermit · February 19, 2011, 08:38 AM

Quote:

I would like to stay with the 06 because I hunt elk and heavier bullets are needed.

If my memory is correct, .308 barrels have a twist that optimizes 150 grain bullets and 30-06 barrels have a twist that is intended to stabilize 180 grain bullets. So (if my fuzzy memory is correct), such a re-chambering would not make sense if the OP wants to re chamber to use heaver bullets.

**Unclenick** · February 19, 2011, 05:29 PM

Dahermit,

Actually the common 10" twist in .30-06 military barrels came from stabilizing the old 220 grain round nose Krag bullet. They just kept it when the .30-03 and later .30-06 were developed. For .308, the army started with a 12" twist n the M14, IIRC, which is just fine for even 180 grain bullets if the air conditions are normal. The military marksmanship units later switched to 11" twists, but most civilian .308's I see these days are using the 10" twist same as the .30-06.

Scooby,

300 fps is pretty optimistic. If I look through my Nosler Reloading Guide No. 6, the maximum velocities they list for their fastest loads with 24" tubes on both are:

Code:

Bullet    .308     .30-06     Difference

125 gr. 3284 fps  3418 fps     134 fps
150 gr. 3001 fps  3056 fps      56 fps
165 gr. 2910 fps  3002 fps      92 fps
180 gr. 2718 fps  2872 fps     154 fps

There are some new higher speed powders from Alliant and Hodgdon. I don't know yet how these will stack up. Take a look through other load data to get a better idea what's out there. Hodgdon's site is another place you can look.

February 15, 2011, 11:35 PM	#26
scoobydoo6906 Senior Member Join Date: July 10, 2005 Location: Portland, Or Posts: 306	aftermarket barrels run $300+ without the chamber cut. I can't see how re-reaming a new chamber would be any more than cutting a new one into a new barrel. I think even with the new barrel you still would want to square everything up even the barrel. if everything ends up costing the same I would get a new barrel but I don't see that being the case __________________ Remington 700 BDL, Yugo M70B1 , Remington 870 wingmaster, Pre 64 Fn Mauser, WASR-10, Mossberg 500, S&W M&P-9, S&W M&P-9c, Mossberg 1500, AR-15 X2, Ruger 10/22, Kahr CW-9, Ruger P-89, Yugo SKS

February 17, 2011, 11:10 PM	#27
lefteyedom Senior Member Join Date: September 7, 2010 Location: Virginia Posts: 333	Scooby, I have a 26" barrel long action 308. There really is nothing that a 30/06 can do that this 308 can't. If you get a chance to chronograph loads from a 308 and load from a 30/06 you will fine very very little difference. The difference often goes towards the 308. A heavy 308 is a sweat shooting rifle, with little felt recoil. The accuracy greatly increase ones confidence in the field. If you feel that the 308 is not enough gun for your elk hunting needs then you may want to make the jump to a 300 Magnum class or larger. I have a 338 Win Mag for my Elk, Moose, Mastodon needs. Build a long action long barrel 308 and try it. If you don't like it have it rechambered to 300 Winchester. __________________ Superman, you are a mean drunk

February 18, 2011, 04:56 PM	#29
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,061	Scooby, Brownells used to send a list with their catalogs to dealers of suggested service prices. Back in the early 90's it was $40 to rechamber. Today it's probably $60-$80, but that's just labor. If Reamer rental is involved you'll have to add that. You still have the issue of whether or not there is enough metal. If you have something beefy like a Shilen #7 contour barrel to start, you'll be fine because the thick portion goes forward of the receiver 4". But if you start with a light sporter one, like a #3, where the thick portion is only 2.5" long, you may not. That will have to be determined by the gunsmith. But I would think that in most instances there will be enough to go from .308 to .30-06 AI because you don't need to set the shoulder back or re-thread the barrel. If you went to regular .30-06, the added labor is unlikely to make it as worthwhile. If you load the .30-06 and the .308 to their respective SAAMI maximums (60 kpsi vs 62 kpsi), you get about 100–150 fps more velocity out of the .30-06 from a 26" tube, depending on the bullet weight. Add another 50 fps for the AI format, and you should have a 200 fps advantage over the .308. It's not magnum but it's not nothing, either. With commercial loads you often don't see that .308 and.30-06 difference because the latter is more likely to be underloaded out of liability concerns for old rifles. The velocities were much closer when both were constrained to using 4895, which the .308 handles more efficiently. But the '06 can actually handle a slower powder better than the .308, and that picks up its potential. You just can't count on using a slower powder in the Garand or other gas guns as readily. Loading for yourself, you can work up reasonably to maximum performance for your weapon. If you work up based on brass pressure signs, you'll likely discover your gun is happy running .30-06 AI at the same pressure as .308, in which case another 25 fps will be picked up. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

February 19, 2011, 05:08 AM	#30
scoobydoo6906 Senior Member Join Date: July 10, 2005 Location: Portland, Or Posts: 306	according to noslers website the difference in a 180 grain bullet is more like 300 fps. __________________ Remington 700 BDL, Yugo M70B1 , Remington 870 wingmaster, Pre 64 Fn Mauser, WASR-10, Mossberg 500, S&W M&P-9, S&W M&P-9c, Mossberg 1500, AR-15 X2, Ruger 10/22, Kahr CW-9, Ruger P-89, Yugo SKS

February 19, 2011, 05:29 PM	#32
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,061	Dahermit, Actually the common 10" twist in .30-06 military barrels came from stabilizing the old 220 grain round nose Krag bullet. They just kept it when the .30-03 and later .30-06 were developed. For .308, the army started with a 12" twist n the M14, IIRC, which is just fine for even 180 grain bullets if the air conditions are normal. The military marksmanship units later switched to 11" twists, but most civilian .308's I see these days are using the 10" twist same as the .30-06. Scooby, 300 fps is pretty optimistic. If I look through my Nosler Reloading Guide No. 6, the maximum velocities they list for their fastest loads with 24" tubes on both are: Code: Bullet .308 .30-06 Difference 125 gr. 3284 fps 3418 fps 134 fps 150 gr. 3001 fps 3056 fps 56 fps 165 gr. 2910 fps 3002 fps 92 fps 180 gr. 2718 fps 2872 fps 154 fps There are some new higher speed powders from Alliant and Hodgdon. I don't know yet how these will stack up. Take a look through other load data to get a better idea what's out there. Hodgdon's site is another place you can look. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

February 18, 2011, 02:36 PM	#28
langenc Senior Member Join Date: August 19, 2007 Location: Montmorency Co, MI Posts: 1,551	While reading the posts on p 1, it dawned on me-you cant fool mother nature-or mother gunsmith. AI w/ several more grains of powder to gain 50 fps-not for me. I usually down load for max accuracy anyway.