Legnthening a chamber

[Lee308]

I am using a long throated 34' barrel for long range shooting in a 308. To gain more velocity I need more powder and to use more powder I need more case capacity.
Q. can I lengthen the chamber to accmodate a 30-06 cartridge to gain the extra capacity and not run into dangerous grounds.
What effect will it have on pressures.
I was planing to use a slower burning powder and more of it.

Cheers

 

[rayjay]

Yes you can rechamber a 308 to 30-06. If you have a short action repeater the cartridges will not feed from the magazine. Also, an unfired cartridge will not eject out the ejection port. You would have to remove the bolt to get the unfired cartridge out of the action.

 

[brfun]

on a short action i would think something along the lines of a 30-284 would be better than a 06
Brian

 

[Gundoktr]

If he rechambers to a 30-06 he will need to set the barrel back almost a half inch due to the shoulder diameter of the 308 being bigger than the '06, thereby negating his need for a longer barrel. IMHO, this sounds like a problem about to go somewhere.

 

[harry.hacking@kiewit.com]

Try a 30-06 ackley improved, you won't have to set the barrel back and you would get even more case capacity. I have done this type of chamber change 243 win to a 6mm AI. Works great.

Hack

 

[Preacher]

Improved or not the 30-06 still has a .013 smaller shoulder diameter......

 

[harry.hacking@kiewit.com]

The Print I have shows the shoulder of the 30-06 AI at .454 and the print of the .308 win shows the shoulder at .454.
Just another 2 cents. Whatever you decide to do just make sure that the new chamber completely cleans up the old chamber.

 

[Larryh128]

Shoulder won't matter, the 308 shoulder won't be there.

 

[TRECustom]

Without setting the barrel back and losing that length, the .30-06 reamer won't clean up the shoulder area of a .308 chamber. The .30-06 A.I. will if the original chamber is concentric and round.

If for some reason you decide to lengthen the chamber with a .30-06 std reamer, the chamber will fire form a slight step in the brass where the original .308 shoulder was, but the fired cases will extract and eject without a problem. I saw it done. But if you reload, the .30-06 resize die will have to work the brass every time.

+1 on the A.I. for cleanup and capacity increase. .30-06 ammo and .30-06 reloads will headspace and fire-form in the A.I. chamber.

Good shooting, Tom

 

[Lee308]

Hiyas,
Thanks for the tips and hints, very interesting to know about the AI as I hadn't even thought about that.
Are the reamers hard obtain, dose anyone make them commercially?
Or can I download a print from some where if I need to get one made?
Thanks again for the input
Cheers
Lee

 

[TRECustom]

Piece of cake. Manson Precision Reamers probably has one made up. I ordered a .30-06 A.I. reamer from them about 3 months ago and they had it in stock. Also, they don't consider it a special reamer. It's their regular price for a rimless rifle cartridge. Available with a live pilot or a solid pilot.

Good folks to deal with too.

Tom

 

[Lee308]

Thanks Tom,
I will look them up.
Cheers