Not sure about their sturdiness as far as bottle bombs goes (you should be all right), but my issue with some store-bought swing tops is the tops themselves. If the stopper is not made of ceramic, you will unlikely get a good seal. Most bottlers have moved to plastic stoppers because the ceramic stoppers could screw up the recycle machines.
One suggestion that has been mentioned in the past is to place ballons over your bottles after bottling to see if they inflate while conditioning. If they do indeed inflate, then you have a leaking swing top seal.