I had a similar experience with a Ruger LCP with a C/T laser using magtech ammo my LCP had hundreds of practice thru it and a lot of JHP ammo also Ruger, Magtech and myself all agreed it was bad ammo with no real expert opinion's. I contacted Ruger and Magtech both the the same day the gun blew they both ask that I send the LCP back to Ruger and the ammo back to Magtech which I did. Ruger sent me a new LCP with C/T laser and because Ruger replaced the LCP no CHARGE to me at all Magtech sent me almost two thousand rounds of ammo which more then covered the cost of the pistol and laser. I feel that's how reputable company's treat their customers. I have dealt with S&W for years and have had some minor problems which they have so far corrected, one of which I'am dealing with right now on a Shield 9 again minor. Just my 2 cents worth.
It bothers me a bit that in all of these Kaboom type threads, it boils down to Smith & Wesson saying the gun was fine and the ammo manufacturer saying the ammo was fine. So in the end you are kind of screwed. I read something like your post and think "I should buy another Ruger". It's not that I expect Smith & Wesson to take the hit if they don't believe they are at fault, but as the customer, I would sure be more motivated to buy a Shield 40 if I saw Smith and Wesson dealing with these situations like Ruger. I understand it might be the ammo manufacturer at fault, but as the customer here, it would just be nice to feel like you'd be taken care of somewhere.