Chamber caliber adaptor.

[HABCAN]

Recently on 'Sons of Guns' I saw a chamber adaptor they inserted in a BAR's chamber to convert it to fire .308 vs. .30-06. Strikes me as a useful thing, simple to turn out on a lathe. IS it simple, and what keeps it from being extracted with the fired case?? Anyone out there made one? Anyone? Bueller?

[Swede44mag]

I used to see adapters to shoot a .22cal in a .22-250 and others.
Check Brownells website they may list one.

[HABCAN]

Swede, thanks, but NO, I don't mean 'cartridge adaptors' in which you fit a sub-caliber round to fire in a larger chamber........those have been around for decades.

[kywoodwrkr]

Look at the dimensions of both cases side by side as well as the chamber dimensions.(SAAMI.org)
Maybe this link will help also.
http://smith-wessonforum.com/lounge/215898-308-30-06-a.html

[Artful]

Google up "Navy Sleeve" - this is what the rifle team came up for their Garands when we changed from 30'06 to 308 and they already had target rifles set up. - Held in place with something like loctite - need heat to remove it.

http://m14forum.com/m1-garand-accuracy/105241-308-garand-history.html

[HABCAN]

Artful, THANK YOU!! That link told me all I wanted to know!!

[longbow]

I had a friend who bought one many years ago but used it in a .30-06 bolt action. It seemed to work fine for him.

As Artful says, Loctite or similar should work fine. I think my friend used epoxy.

Longbow

[TCLouis]

I understand they made them to convert VZ-52s from 7.62X45 to 7.62X39, but like the 30-06 to 308 adapter sometimes would eject with a spent casing.

Real issue or internet fabrication . . . I don't know

[edsmith]

those chamber adapters have been around for a lot of years, if I remember right, they said to remove it with a broken shell extractor.

[Multigunner]

I understand they made them to convert VZ-52s from 7.62X45 to 7.62X39, but like the 30-06 to 308 adapter sometimes would eject with a spent casing.

Real issue or internet fabrication . . . I don't know

The 06 to 7.62 adapters also ejected along with the fired case every so often. From images of 7.62 cases that had been fired in one of those Garands after the adapter popped out it seems this wasn't disasterous.
Some Chilean 95 Mausers converted to 7.62 had a cylindrical sleeve fitted into a the shoulder and throat area of a bored out chamber.
They rebored those 7mm rifles to .308 bore size but this left the mauser chamber still too long to simply rechamber the bored out barrel.
They soldered these adapters in place, but from images of a sectioned barrel the solder seems to melted away after awhile, possibly partly dissolved bt strong bore cleaning solvents, leaving a thin gap in the throat.

I think the altered barrels were rifled after the insert was installed.

Similar inserts have been used on MG barrels but not for the same reason. Those inserts were made of Stelite alloy to reduce throat erosion and extend the life of the barrel.

There are probably adhesives better suited to holding adapters in place, newer glues that are heat resistent.

[W.R.Buchanan]

I have seen several of these adapters in use in the SKS 7.62x45 to 39 application.

They were poorly made and even with green loctite they wouldn't stay put thru a whole magazine of shooting. Green Loctite is what you use to take up the slack on a loose bearing fit, so it is the right stuff to use for this application.

If the original chamber is tapered as most are I really don't see how you would hold the thing in place for any length of time.

If you put grooves around the outside of the adapter and grooves on the inside of the chamber and then epoxied it in, there would be something to mechanically hold the thing in place. At least until the glue broke down.

This is one of those things that I would just never do unless I absolutely had to.

My .02

Randy

[hunter2]

MCA Sports out of Alaska makes these and a lot of other stuff. (45 acp, 22, 380, 38 etc.. Can hit coke cans at 30 yds in a 20 ga TC Encore. )308 - 30-06 Acc suffers a little from the ones I have seen. But they work pretty good. Did see a fellow fire 10 rds. of 308 through a 30-06 with no ill effect. A lot of discussion both ways and one decided to show that it would work. Too busy watching the gun to see how it grouped.