308 chamber adapter in 30-06 garand, crazy question.

[Crosshair]

OK some are going to think I am crazy, but here goes. When I get my garand back from the shop I plan on adding an adjustable gas plug to it. I was wondering if I could use the chamber adapter available here to shoot 308 out of my Garand. The twist on this is that I don't want to glue the adapter in. I would set the gas plug to make the rifle into a straight pull bolt action when using it. The brass would then be able to shrink back from the chamber walls and be less likely to pull the insert out. (It probably will anyway) Since I am manualy cycling the action I would be able to check the spent brass and see if the adapter had been extracted with it. I want to be able to use cheaper 308 ammo for plinking, but be able to have a full 30-06 round with little work. It also makes sense from a SHTF senario to be able to use different ammo. I don't see a problem with the adapter not being glued in, other than the fact that I need to be sure it is in the chamber when using 308. People use them in bolt actions without any trouble.

 

[cracked butt]

This is just guess on my part, but I think you would want it glued in place. If it moves around between shots, I would imagine that accuracy would suffer pretty badly. Another thing to consider is that if there isn't some sort of significant tension holding the insert in place, I think that you would be putting most of the pressure of the fired cartridge on the boltface instead of distributing a large portion of it to the chamber walls, putting undue stress on the locking lugs of the bolt.

All of the above is just a semi-educated guess on my part.

 

[straightShot]

I have a friend who put one in his Garand to shoot .308. He loves it, but the first few times that he fired, it ejected. I believe that he used loctite later to solve the ejection problem.

Be careful so that you don't fire again if it should eject.

 

[TMM]

you could get an M1A which is chambered in .308win, but that is more costly than a gas port plug thingie... but then you could shoot semi auto. and it an excuse to get another gun. =)

~TMM

 

[444]

I have a few adapters similar to the one you linked to (.30-06, 7.5 Swiss, 7.62x54R), although from a different company. It would certainly work. There is only one problem that I see: .32 ACP ammo is not cheap. Surplus .308 might be cheaper, but then, so is surplus .30-06. And of course the cost of the adjustable gas port: IF you are doing it just for this purpose which I am sure you are not.
It wouldn't hurt anything, although it would be a pain, to just let the adapter eject. But, the gas port would be a great addition (and this is coming from someone that doesn't buy into the modification of milsurp rifles).

 

[Jim K]

The chamber adapter to use .308 (7.62 NATO) in a .30-'06 rifle is not a good idea. First, to work properly, it must be installed permanently, and in addition, a .308 chambering reamer must be run into the chamber because the .308 is wider at the shoulder than the .30-'06 is at the same point. If the chamber is not reamed, the .308 will wedge in the chamber and it will be very difficult to extract and unfired case. In other words, the conversion is not irreversible, but is nearly so.

Also in a gas operated rifle like the M1, the gas port should be smaller for the .308; it will function with the .30-'06 size port, but not as reliably. Clips will also be harder to load due to the aforementioned width of the the newer case.

IMHO, if you want a .308/7.62 NATO M1 rifle, rebarrel and be done with it.

(Just FWIW, .308/7.62 NATO can be fired in an unaltered M1 rifle with no problem except an odd looking fired case, but extraction of an unfired round is difficult and the practice is not recommended.)

Jim

 

[444]

After re-reading my post, it was kind of confused. On that page you linked to, there were a number of chamber adapters: .32 ACP in .30-06, 7.62x39 in .30-06, .308 in .30-06.
The only ones I have actually used is the .32 ACP in a .30-06. That worked fine. I never used in in an M1, but I don't see where it would be an issue: other than the fact that it would be ejected.
I somehow lost the fact that you were asking about the .308/.30-06.

 

[P-32]

The US Navy tried the sleeve thing and found it to be unsat. (Navy Mk 1) SA made some fine 308 barrels and they ended up on Navy Mk 2's. If you want to shoot 308 in a M-1 have it rebarreled. Clips load the same way and are not harder to load. I like my 308 M-1 but I also like my '06 M-1. Unfortunately, you can't have it both ways.

 

[Crosshair]

Remember, I will be using the rifle basicly as a straight pull bolt action with the adapter in. I'm thinking about doing this just because I can. I am getting the gas plug anyway so I don't wreck my op-rod with hot 30-06.