30-06 to 308 chamber adaptors??

[NYH1]

Has anyone ever used a 30-06 to 308 chamber adaptor? I have a Remington 7600 Carbine in 30-06. I have a bunch of good 308 hunting ammo. I saw a few 30-06 to 308 chamber adaptors on some sites, most guys use them on BAR machine guns and that type of stuff that was originally made in 30-06. I'd like to know how well they'd work in my carbine. Any thoughts?

Thanks, NYH1.

 

[Edarnold]

The problems with the .308 adaptor is that it may or may not stay put in the chamber. If it ejects with a fired case, the next round will be going into the original chamber: given the bolt setup on your 7600 it will probably be pushed forward into the longer chamber and not fire. May or may not come out easily, so you may have a disabled gun until you push the round out with a cleaning Rod. The second problem is that the 1/2 inch of the adaptor has no rifling, so you have a very long lead, which may effect your accuracy.
Personally, I think you are better off trading your .308 ammo for 30-06 and use the gun the way it was intended to be.

 

[joshk1025]

Like edArnold said, you don't want it coming out. You might keep it in the chamber with loctite or similar with good results, but that would be a rather permanent solution. As to accuracy, I know some of the 308 garand conversions using chamber adaptors were quite accurate, and if you are hunting rather than punching paper, I would guess probably accurate enough

 

[Willie Sutton]

The so-called "Navy Sleeve" was an attempt to convert the M1 Garand to 7.62x51 by the Navy, using the sleeve and a magazine block to shorten up the magazine area in the receiver. They met with limited success but do work. I installed one into a shortened "Tanker" Garand many years ago when they were the rage, using a VERY thin bit of epoxy on the sleeve, after degreasing the chamber and sleeve completely. These are then inserted and fire formed by firing a cartridge to upset the fairly soft steel they are made of into the chamber. They can be removed by using a ruptured cartridge extractor. The one I installed was still running strong when I sold the rifle, having shot some 1200 rounds thru it. They are destroyed when removing them with a ruptured cartridge extractor.

I've always thought a handful of these tossed into a spares box would be a good hedge against not being able to get .30-06, but with that seeming unlikely never bought another one.

I would say to use these with cautious optimism.


Willie

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[Art Eatman]

I guess back in the '60s/70s', a guy was advertising these adaptors in Shotgun News. From a shop in Montana, IIRC. From time to time in the gun rags, somebody would write in and ask. A fair number of responses were much like Willie's, with a random number speaking of the problem mentioned by Edarnold. I haven't seen much about them in recent years.

 

[Reloadron]

While Willie and Edarnold covered it well one problem I have seen is accuracy falls off. Using for example a 30-06 Springfield to 308 Winchester increases the chamber leade or bullet jump considerably. For example a 30-06 chamber headspace minimum is typically 2.0487" while a 308 chamber headspace is 1.630" minimum. Looking at cartridge length a 30-06 Springfield cartridge comes in around 2.494" Maximum while the 308 Winchester comes in around 2.015". I have even seen chamber adapters to go from 30-06 or 308 to 7.62 x 39 so go figure.

So while chamber adapters do work I don't care for them from an accuracy point of view when using them. Maybe in some hunting rifles the effect isn't as great, I am just not the one to suggest using them.

Ron

 

[NYH1]

Thanks guys.

 

[joed]

I have to ask why you would want to use .308 when .30-06 is available almost everywhere.