I am personally not recommending TULA brand ammo. We are seeing it display primer-flow. As such it is eating breech-faces. We've seen it on Wilson, Ed Brown, Kimber and Glock pistols.
Glock has even gone so far as to start telling their cadre to not recommend TULA brand ammo.
I am aware that TULA is supposed to be the same ammo as Wolf and the like, even from the same factory, but we are only seeing it on TULA label.
A Cabellas was forced to pay for pistol replacement since they sold the ammo to a customer as well.
As for steel case and all that stuff, I have no concerns. It runs fine and isn't a problem. It's training ammo.
If I had a few cases of it, and I was reading this post, I would still shoot it. I just would check the breech-face before every shooting session. What's it's condition? Every few mags, I would take 1/2 second to look at the BF. If it exhibits erosion / pitting I would stop shooting. A little pitting, while not preferred is not a deal killer in itself.
If you let it go and it becomes worse and worse, that is when you will have problems.
As to why this is happening, we can't be sure. It's NOT pierced primers. It seems to be low quality primers that don't seal the pocket properly.
TTR