Originally Posted by RAF
did you have the same problem ?
And some. There were a good few others too. I know of two other shooters who gave up on them. One had been to our local AA guru in Essex and had the AT removed and internals fettled and it still wasn't right. Mine started ok but then developed a similar 'flyer' problem, every 5th shot would be a flyer. Then it would be fine for a couple of weeks, then it all started again.
Having said all of that. There are more very very good 900's than bad ones and they've become very popular. A friend of mine has one and it's very accurate.
If it's new, send it back. If you bought it used you'll have to follow the advice that will come following your post.
I apologise for not having answers, I gave up on mine fairly quickly, my head was turned by Daystate's Pulsar, and that's a whole other adventure
I'd certainly start by shooting longer strings. If there's a pattern, higher shot counts will reveal it for sure. It might be random, it might indeed be every fifth shot.