I have to start this post with an apology to FailZero: I did many bad things to your bolt and you aren’t getting it back. I hope that’s okay. Back in April I received a FailZero AR15 BCG with no hammer. Their products come with a Nickel Boron coating, which they call their EXO Coating. You can view the product here on their website which retails for $185. The included EXO coated hammer version retails for $200. They also offer M16 bolts that are full auto rated as well as offer their coating services for other firearm products.