Nice find! When I was working part time at the old Morris Sporting Goods store in Great Falls, Mt., I'd see maybe a couple of these a year come through. Most of the time, they were sold while still being cleaned up, and I don't recall seeing the same gun twice. They, like a lot of really interesting guns, came from AF GI's who were stationed at Malmstrom.
Looking back through the fuzzy haze of a fractured memory, I don't recall seeing any with Sako actions for the .473 and H&H belted case rim sizes, all of 'em as I recall, like yours, used Belgian Fabrique Nationale actions, the same basis for the Browning Safari line, and a lot of the Husqvarna's. Seems like the little .222's and .223's had the little Sako, but I could be mistaken.
Didn't get a lot of reports back on how they shot, most guys were interested in how light they were, and at the time, about all that would compete with 'em in that category were the short barreled Remington 600 and 660's, some lever guns, and custom bolt guns. I can't imagine touching one of them off that were chambered to .300 Winchester Mag.....