I used to shoot tons of Blazer and I see a lot of it at the range. I've only witnessed a few issues...no more so with Blazer than any other factory ammo.
I've seen an up-side-down primer or two. And, I've seen where the bullet is over-seated and pushed waaaay down into the case...which could mean a few things, but you wouldn't want to shoot a round like that.
I'd test some of that remaining ammo to see if there is good tension on the bullets. (measure the bullet's overall length, press it against your bench/counter with some thumb pressure, then measure again to see if it shortened)
If you think you have a bad batch, gt in touch with CCI...they will likely take care of you.
Also, give your breach face a real close looking over for any damage. Make sure that your barrel is clean and clear while you are at it. (Good idea to check the gun over closely, since you just had an issue.)
The odds of having a factory ammo issue are probably more like one in tens-of-thousands range. (I trust my reloads more than factory.)
If you shoot 50,000 rounds you likely see an issue or two...with just about any factory brand.