What is this thick steel chamber adapter looking thing.

[swampratt]

Looks like a chamber adapter but the hole is centered and is .004" smaller than a 209 primer.
It is steel and 3/4" long and the ID is .22 caliber diameter.

.470" diameter at the fat part of the body.
Does not taper and it does have an extractor groove.

Without the taper I think .308 is not possible but maybe 6.5x55.
I thought it was for gun salute using a 209 primer.

Just a wild guess though.

The hole goes all the way through.
It was in a bag along with a dozen more and in a reloading box some guy had.

 

[dennishoddy]

Looks like a chamber adapter but the hole is centered and is .004" smaller than a 209 primer.
It is steel and 3/4" long and the ID is .22 caliber diameter.

.470" diameter at the fat part of the body.
Does not taper and it does have an extractor groove.

Without the taper I think .308 is not possible but maybe 6.5x55.
I thought it was for gun salute using a 209 primer.

Just a wild guess though.

The hole goes all the way through.
It was in a bag along with a dozen more and in a reloading box some guy had.
View attachment 499789View attachment 499790

That's what the hole looks like when I modify a round to fit a 209 primer.
Works great using .223 brass and a .22 caliber pellet. It will go completely through a 2X4 with zero powder.

 

[mr ed]

maybe it was for the old 157 or *97 Remington primers

 

[Paul Box]

I think Dennis is pretty spot on or maybe one of these in a 222 format by the looks of the neck and shoulder.
This is a pic of a 223 conversion to 22 mag, I also have one to convert 22 LR.
I've seen both for with or without full loads.
They were produced for a single shot similar to the Thompson Center Contender.