I hope the problem is fixed! It really is one of the worst type feelings about any kind of gun that has acted up and especially one that may be used for serious DG hunting. It's always in the back of the mind. I've had a couple in the past that acted up like that.
The more rounds without a hiccup the better of course. A test I've done after working on bolts and strikers and springs and such is to fire a few of the toughest to ignite primers available. I figure that if it fires those with no problem it's likely good to go with normal, easier to ignite softer primers.
The CCI 34 is a large rifle primer with a thicker/harder cup specifically designed to prevent "slam fires" in military type auto loaders where the phenomenon is possible. I just load up two or three in empty, resized cases and fire them. I then do the same same with regular primers.
Left is an empty, resized case fired with CCI 34 primer considered to have one of the hardest cups. Right is an identical empty, resized case fired with a Win primer considered about average for ease of ignition and cup hardness. Note the very small pin dent in the CCI 34 primer compared to the more normal sized pin dent in the Win primer. And even the relatively small primer impulse appeared to slightly flatten the cup against the bolt face in the Win example.
