I sure wouldn't fire back-to-back shots with them.

I would be tempted to disassemble a couple of good rounds and see if the wad is damaged/malformed. There must be hot gases escaping up past the wad on ignition. And I would think that if the cause was cheap plastic case material that it might be noticeable from the outside (discoloration?)

It looks like crimp for whatever reason is stronger than the side of the shell. In other words, it takes less effort to tear the wall of the shell than to open the crimp.

COB used those shells in 28g here last year at our four day event. He was shooting a graded 28g and one of the shells bulged his barrel. If I remember correctly the manufacturer said they would take care of his gun. That's the last I heard. You'd have to ask COB what became of the gun.

I've used their shells in 12g and 20g with no problems. I shot in a charity event at Hausmann's where the same shells were given to every entrant, also with no problems. As for "cheap", they are certainly not! Morris actually pressure tested their shells and said they were truly low pressure as advertised.

Most likely what Remington engineers called an “occlusion”; a piece of foreign material was in the plastic and did not allow complete homogeneous material when extruding. “Dirt in the mix”. The partical could end up anywhere in the mixture. We would see them on occasion. Just need to make sure nothing is left in the barrel.