Utterly Mad

Who mauled a perfectly good rifle to make that? I can't tell if the stock is original, or if maybe somebody took everything but the stock from a small rifle and attached it to the stock for a larger rifle. Trying to compare it to nearby objects only makes the barrel/receiver/action assembly look smaller. Hell I went to look it up and found lots of images and pages showing and talking about perfectly normal looking rifles. Who did this thing? Who mutilated a fine example of rifle craftsmanship to make this?

EDIT:
Found this.

Spoiler (hover to show)