[Firehand]

Besides the barrel change- and the magazine block if you choose- is there anything else that has to be changed out? Op-rod spring, for instance?

[glockster157]

I am not sure of a professional change out but I use one of those 308 chamber adapters to shoot 308 in my 1944 springfield. So far it has worked great and I have had no problems. So if you had a 308 barrel installed and find one of those blocks that goes in the magwell (I don't have one but if I were going to go to a 308 barrel I would get one) it should work fine.

[Firehand]

Glockster, did you use loctite or something to hold the adapter in place?

What kind of difference in POI did you find when went to .308?

I've read of the adapters, with a number of mixed reviews as to how well they work.

[glockster157]

I did not use locktite....as a matter of fact I went the other way and I would recommend to anyone that trys one to use anti-sieze lube. The first time I used it I did it dry and I had cleaned the chamber and the insert with acetone. I then used a broken shell extractor to remove it but it gave me fits. I use some penetrating oil and got it out. If you wanted a permant change to .308 then use Locktite. With anti-sieze on the insert the next couple of times it popped right out. As to accuracy, I did not bench the gun. But I was able to hit the gallon jug size targets at 100 yards. I was just plinking with the berdan primed stuff. Hopefully, this summer I will have time to bench it with both 308 and 06 and see the difference. I ran about 10 clips through it and it ate them without a bobble.

[Jim K]

Glockster, if you didn't run a .308 reamer into the chamber, don't you have a problem extracting an unfired case?

IMHO, Glockster's experience is better than most in using an adapter. The problem alluded to above is one drawback, another is that the adapters sometimes come out along with the empty case. (Not that it makes that much difference; the M1 will merrily shoot 7.62 NATO all day without any adapter, but extracting unfired rounds is very difficult.)

FWIW, a barrel change is the best route; that way you get the right chamber and the right port diameter for 7.62 NATO/.308.

Jim

[glockster157]

OK, I have to ask, why is it so difficult to extract a 308 round from a 30/06 chamber? Is it the body taper or something? Because I also put the insert in my browning A bolt 30/06 and test fired a couple of rounds and used my broken shell extractor to remove it. It worked as far as function but I did not test any further. The Navy was the one that developed the insert concept, at least that is what I have read, and they also had many Garands converted back in the 50's. Of course a purpose built gun will work better, but I only want to shoot 308's in an emergency. 30/06 is still readily available for now.

BTW, you can shoot the 30/06 chambered rifle with the 308 ammo. I would not want to try that with no insert.

[Jim K]

The .308 is larger at the shoulder than the .30-'06 is at the same distance from the base. The result is that if forced in, the .308 wedges into the .30 chamber. This supports it for firing and the M1 op rod spring has enough power to force it in, and it will fire and extract fine. But if a round is not fired, or misfires, it often can't be gotten out without a lot of force.

But in most .30-'06 bolt guns, the .308 can't even be forced into the chamber; if it is, it jams and trying to remove it can result in a broken extractor.

Firing .308s in an unmodified M1 works fine, and produces what look like rimless .45-70 cases. I don't recommend doing it very often, though, because you could get erosion in the chamber neck and throat, plus copper scrapings in the chamber mouth.

The use of a magazine block is OK but the reason often given for them is absurd. Supposedly, they are used to prevent accidentally firing a .30-'06 in a .308 chamber, which is nonsense. What they really do is prevent the short round from jumping forward in recoil and jamming the rifle, the same purpose the bullet guide serves in the original rifle.

Jim

[glockster157]

I took the time to re-test the chamber adapter with both my M1 and my Browning A-Bolt. The M1 worked fine, though the adapter was a boogar to get out this time but I have to eat crow own the Browning. I don't know if it was factory 308 I used last time or some reloaded ammo, but with the current batch of Malaysian 7.62 I have will not chamber the Browning with the adapter :o . Just goes to show that if you try something unconventional, you shouldn't assume the first result is always the correct one. Anyways, since I have a 1000 rounds of 30/06 boxer primed brass cased ammo and only 200 rounds of 7.62 left, I don't think I am going to even bother with the adapter anymore. I will keep it for emergency (SHTF) use in case I have to have a rifle and all my 06 is gone.

[GCW5]

I maybe silly, but it seems to me that I read some where that the gas port in the barrel needed to be drill out a little bigger to get enough gas into the piston to function properly with a .308, and that once that was done, it wouldn't be able to change back to 30/06.

If it works OK with just an adapter, it would be fun to run some of that cheep surpluss stuff through and keep the 30/06 for buisness

[glockster157]

I never ran into a problem, except removing the adapter, shooting 7.62 nato in the Garand. Both work in the 50k cup range and if anything, the 7.62 nato is loaded to higher pressures than the 30/06. Mainly because there are so many older 06's out there.

[bobsmith]

I have a M-1 Garand that I rebarreled with a Barnett .308 barrel. I did full National Match accurizing on the rifle. It shoots very well.

Be careful about using the chamber inserts. Originally the military used them but discontinued the practice when they found that inserts would work loose and eject unknowingly. The result is that the next round in the chamber is in an excessive headspace condition which can lead to all sorts of problems.

[glockster157]

I am selling my remaining 7.62 ammo and saving the insert for emergency use only because I still have quite a bit of new, reloadable 30/06.

[BILLY D.]

glockster157

May I ask where you got the insert from?

Thanks, Bill

[glockster157]

They used to advertise them in the Shot Gun News way back when. I think I got the insert for $30 and the broken shell extractor for $6. But that was a long time ago.