Going back to the OP...I've had my Ljungmann about 30 years now. When I acquired it both Remington, and Winchester made SP ammo for hunting, and it was at the closest can-tire. The Remington didn't cycle well, and occasionally the bullet would get pushed back into the case while cycling, the Winchester worked ok. The rifle came with Norma ammo too. I n'er really used the NOrma because even at that time it had $40 stickers on it (That was all launched by my brother!!!!). The Winchester and Remington was about $14/20, and surplus (Norwegian) was $8/15rds.
In the last decade I have launched S&B, and Privi quite happily through it.
In 3 decades the rifle didn't change, only my awareness did. I didn't reload so didn't care where brass landed, or how mangled it was when it fell back to earth. I didn't notice any single ammo made the action "violent" as they all seemed to. I had only 1 misfire (slam fire?), and that was during a time when I had no magazine. It was touched off when the bolt shut on a pre-chambered round. (Winchester ammo if that matters) The extractor broke during that event (It was close to the 100th no-magazine-fired round), and in the course of finding an extractor learned a lot about the rifle.
About a year ago changed out the gas-port screw (call me Bubba as the original screw got marred during removal), but haven't done too much with it since.
...kind of long winded, but personally I would have no issues running S&B, Privi, or even Winchester factory ammo through an un-altered Ljungmann. Have seen Winchester ammo pass through a Ljungmann(not mine) on it's way to seals a few times.