We've got a know your limit rack at our range that's at 256m, and the target sizes are 8", 6", 4", and 3". The first couple I can hit consistently on a calm day, the 4" is maybe a 50% hit rate in calm weather, and the 8" is doable for me if the wind isn't too bad. I'm shooting my Norinco NS522 with CCI SV and SK standard +. I've got a brick of SK rifle match to try out now too, but what's probably holding me back more than ammo is lack of shooter skill, especially when it comes to judging the wind. I've shot two rimfire PRS matches now with this rifle, and have managed around 50% of my match hits. Lots of practice is needed, and I've seldom shot from positions other than prone or a bench. The first match I shot had one target at 412m, but I timed out before getting to that target. It was the first match stage that I had ever shot, and the first time shooting a rifle with any sort of time limit.
Kristian