Got a reply from Ben today and it explains everything! i figured the SS wasnt up to par, my brother said it looks paper thin and sure enough!

Sorry about your experience, Jonathan. As I explained to you, the first Mag Spark was not oversized (6mm is approximately .236”). The threads appeared to be off on the profile, probably the angle was slightly off, However, the replacement was defective in a much more serious way. The manufacturer decided to improve on my design and made several changes to my specifications. One of those changes was that he cut the M6X 1.0 thread too far toward the primer cup, resulting in a thinner than necessary wall. This caused the failure that you experienced, not inferior metal. I invented the Mag Spark system over 30 years ago and I have sold thousands of them worldwide, without a single failure of this type. Until two years ago, I made them myself, on my own equipment, then, due to my age and other factors, I decided to have them made by someone else. That is the first time that I had problems. That being said, it is my problem. The Buck must stop here. I am currently looking for a company to make the Mag Spark to my specifications. Meanwhile, Paul and I will decide what to do about the ones that we have on hand. Again, I am sorry for the problems that you have had and I will see that you get your money back. Ben Hubbard