Images from Official Handbook, circa 1908:

Hmm, that contraption might be the answer to the stock cuts on that .22 Krag too.  Not seeing any such attachment to the Wilkinson Sword variety of the machine, but there are some images of it being used with the Krag here:  (You need to Login to view media files and links)

I posted this under the topic "Krag Grading" where the question was about a carbine marked PSAL-NYC.  I thought I would copy it over here.

PSAL?  About 4 years ago, I was doing some research for an article I wrote about Winder Muskets.  I came across 4 issues of the NY Times, about 1907 & 1908, in which they reported on something called "schoolboy matches" held as a part of a big sportsmans' show, maybe in Madison Square Garden.  The issues were 2 consecutive week-ends, maybe in April (?) for two consecutive years.

The article reported the boy shooters names & scores and told which school they represented.  It explained that the match was shot with .22s on a range on the main floor.  After the match, the boys were allowed to go to the range in the basement, where they were allowed to shoot the Krag and the Maxim gun.

When I read that, I could not imagine letting high school kids shoot a Krag with 220 grain military ammo in the basement.  I assumed that the kids were shooting GPRs.  Now I am not so sure.  There was an official gallery load for the Krag.  It was reportedly quite inaccurate, which led to the Stevens-Pope conversions, the subsequent Army political flap and the eventual production of GPRs in 1907-1908.  I assumed that with the GPR, the Krag gallery load was abandoned.  But surely enough could be found to let each kid bang away with a Krag a few times.  I further assumed that the kids were allowed to touch and play with the Maxim. After this, I am not so sure.  If allowed to do so, I would be first in line to fire a Krag gallery load in a Maxim.

My view is that PSAL-NYC may well increase the value of that particular carbine, if some supporting documents can be found.  There are still thousands of complete & authentic carbines and tens of thousands of similar infantry rifles.  But has anyone ever seen that stock marking before?

Outstanding research!