Seal shooting, according to W. Greener, Gunnery, 1858, page 404.

"The effectual and instant killing of seals on the ice is an illustration; failing to kill a seal dead, he will, to a certainty, reach his hole in the ice, and disappear, to the shooter's serious disappointment. Small bore elongated bullets were very rapidly adopted, and as readily abandoned. 'They did not kill dead;' the spherical bullet did this better. It would be wise to pause and consider whether a good military rifle is a good game-shooting rifle or not: whether the hole in the beast be wide enough. I am inclined to think the reduction to a bore of 25 too small for this purpose."

This is probably the reason for the, what appears to be a fairly large bore English Style muzzleloading rifle in the 1904 picture. They worked.