I believe that was an improvised adapter so 'Blank Cartridges' could be fed through the magazine.

Likely done for a Veterans' Group Honor Guard.

Hollywood 'prop guns' for the movies also had such alterations.

Possibly replacing  the Side-Plate will restore magazine function.

Now that makes sense, thank you!

Good point Fred, it could be.

I suspect this brass device was to feed .30-40 blank cartridges, but ....

He needs to visually check the chamber to make sure if it has not been altered.

If there is anything suspicious, a 'chamber cast should be done.

Here is a photo, (that a fellow KCA member posted years ago), of a .30-40 cartridge-case fired in a chamber crudely altered to accept .30-06 blanks:

'fatdog' - This will make you happy.

IMHO - (This kind of stuff is why every Krag enthusiast should eventually buy and own the late Frank Mallory and William Brophy's books)!

Page 184 from: "The Krag Rifle Story", 2nd edition, by Franklin Mallory.

Your adapted Krag may contain an Arsenal produced device. Relatively rare - IMHO!

Please show us more, (clear detailed pictures), of your "adapted" Krag rifle and carbine.

This kind of 'oddity' and member sharing is why I love the KCA site.

William Brophy put a very clear photograph of the 'blank device' in his book, "The Krag Rifle", page 135.

From what I gather: (The original blank cartridges for the U.S. Krag, had a 'paper bullet' containing a black-powder charge. This paper projectile allowed feeding through the magazine and the paper bullet disintegrated upon firing, as a safety measure.
The pre-WW1, M-3 blanks were shorter and without projectile. They required the bronze device and some alteration of the follower in order to feed through the U.S. Krag).

The device, Brophy described, was nicely made, held in place by a Screw through the side-plate, and serial numbered to match the receiver.

(I am 'Persona Non Grata' with Mr. Farmer. Perhaps someone, who has his book and access to his site, can review his materials or ask him).

You've got some tough stuff in Texas!

Why not make .30-40 bird shot loads?

Fred - No exploding bullets for you.

Y'all will burn down the house!

We sure got off track now! With flocks of several thousand hitting the wing at once, if you get 10 or 12 birds per shot you are doing good with dove loads, 3 to 5 is the usual. Really you just drive them away for a few minutes then they are back. You all probably have the same birds up there, you just have not noticed them. They migrate to this area during the winter always a few around but huge numbers in the fall and  winter. Correct name for them is "brown headed cow birds" not to be confused with the white cattle egret which is a beneficial bird.