Too much pressure for the holding vessel is the cause of bottle bombs
Obvious, I know, but the truth. The question is then: what in the bottling process is leading to this outcome? It could be (micro)fractures in the bottle. It could be crappy bottle manufacturing on a handful you used for that batch. It could be that a bunch of bottle banged together at some point and weakened the glass. It could be too much priming solution was used. It could be that the priming solution wasn't well distributed in your bottling bucket causing some bottles to get too much sugar, and other to not get enough. It could be a resilient sacc strain (var. diastaticus) is in your equipment. It could be a wild yeast (e.g brett), or a bacterial contaminant (as mentioned).
There are a lot of possibilities. Are the bottles actually overcarbed? Have you opened one at room temp (outside is best with gloves and eye protection) and seen the impressive gushing? If it doesn't seriously gush out of the bottle then it may have just been a bottle issue, not a batch issue.
While testing a gushing bottle outside, pour some in a glass once the gushing slows down. How does it taste? Is it obvious contamination?