What can this be?

[Papa G]

https://www.gunandgame.com/data/attachments/64/64644-687d91a25cb93d726856cae3e92d9e98.jpg

Looks like a Krag, but what is that attached to the receiver? Thanks to all.

[psteinmayer]

That is a device that connects to a scoring machine for practicing without live ammo. I'm not sure of the name, but there are other pictures out there of the entire device.

[Kragrifle]

Sub-Target Practice Machine. Brophy's book has the best description of the device. I have read somewhere that the city of New York bought 50 of these. Boy, have things "changed"!

[CJCulpeper]

What the?! You mean it is not a rare Springfield prototype full auto selector switch? Dang.

[madsenshooter]

No, but I once ran across a pic of a Krag converted to a machinegun. Some folks down south found it under a bridge IRC.

[butlersrangers]

The Krag with the linkage was adapted for use on a Sub-target Rifle Machine. This was a large apparatus in vogue from around 1904 to 1920.
A rifle with alterations was held in the movable arms of this device. A "shooter", with full range of movement, would aim the cocked, but unloaded rifle, at a fixed distant target. He would dry fire when he had a good sight picture. The act of 'firing' moved a cable (U. S.) or completed a dry battery circuit (Britain), which powered a needle that pierced a miniature target, held in a frame on the machine. This allowed marksmanship training and competition without ammo or range facilities.
This was the invention of Mr. Henry Havelock Cummings of Boston, Mass., where it was manufactured. It was also built in Britain by the Wilkinson Sword Company.
Users of the Sub-target Rifle Machine included: U. S. Military and Naval Academies, Royal Navy, British, Canadian and Indian Army, U. S., British and Canadian military schools, and the N.Y.C. Public School Athletic League.
Brophy shows a similar linkage on a 1903 Springfield in his 1903 Springfield Book.

[butlersrangers]

Photos showing sub-target/score card and various machine features: