An open bolt can be shot quite accurately. The biggest thing for me is that I have to remember to keep the stock tight against my shoulder. I start letting it just sit up there loosely and I start throwing fliers. It also took me a while to figure out, but I can shoot my M11/9 all day with minimal malfunctions. I then hand it to someone else and for some it will jam left and right. I think they are just holding it really loosely and inducing their malfunctions.I think there is a lot out there to give shooters an idea about what would be considered good pistol or rifle accuracy (X-sized group of Y shots at Z yards), but I don't have a good sense of how that correlates for full-auto shooting (e.g. a top shooter can put a 5-round burst in an X-sized group (or maybe more likely an X-sized plate) at Z yards). The single-shot accuracy measures seem fairly obvious, if a bit more difficult with an open-bolt platform.
Yeah - or maybe not. I'll have to go see. But then the smallest-group-burst thing rarely comes up. Being able to accurately shoot a 2- or 3-round burst seems to be a more practical skill for most of the matches I've shot. There have been more than a few instances at the Creek where you had to put a burst into a heavy popper with a no-shoot close by. Single hits weren't enough to take the popper over.I recall in one video Larry Vickers described a challenge where the shooter fires a 10-round burst at 10yds and to see how many rounds can be covered by the shooter's hand as a rough test of full-auto accuracy. I would except a lot of the regular competitors, such as yourself, could keep all 10 rounds in a hand-sized group at distances further than 10yds.
I did shoot a stage at the OH subgun match a few years ago, but I want to say it was just a burst into a paper plate where all hits on the target count for score. The wrinkle was that you had to shoot through a cardboard "wall" with a port in it. Any hits on the wall were a penalty. What was interesting was that almost nobody hit above the port, but many people drove the gun down into wall below the port.