When you set out to build a blowback style 9mm AR, it can get confusing. The right parts make all the difference in the world. You know that any old run of the mill parts won't do. That's when you turn to Odin Works. Problem solved.
If you look around the old interweb, you will find many bolt carrier groups for sale. You almost want to give up and just get one. But, what makes one better than the other. You have to look at the source, their history, and the quality of customer service you can expect. What you don't want to do is grab a cheap 9mm bcg off some questionable website. You might end up with a paperweight.
To be such a small cartridge, a 9mm is a vicious little beast. The round is especially hard on your 9mm bcg. Quality will show, and this is where Odin Works shines. On a website, it's hard to tell one part from another. However, inside your AR, the difference becomes apparent. Odin Works chose 8620 steel for their carrier. Then it's hardened and treated to a Black Nitride finish. The result is a 9mm bcg that is hard, slick, easy to clean, and corrosion resistant. Odin Works went with an M-16, external style extractor which is far superior to an internal 1911 type. You get increased reliability and one less thing on your mind. Additionally, Odin Works designed their bcg to work with either Colt or Glock style lowers and magazines. Therefore, you can build the AR that you want, instead of the one you have to.