I bought a Rainier Arms UltraMatch 5.56MM - 16 upper and right now I am experiencing failure to eject of the spent brass. The scenario is that after firing, the spent case remains attached to the bolt instead of being ejected, which prevents the new round from being loaded. Even if the bolt carrier group is pulled back, the spent case remains attached to the bolt. A little nudge on the spent case when the bolt carrier group is pulled back will allow it to be removed from the bolt. The ammo where I'm seeing the problem occur are the Federal XM193, XM193F, and American Eagle 223. After shooting, I manually did the cycling with some spent brass (Federal/LC) to try to duplicate the problem but I couldn't. I've read on some forums that something similar happened to a certain batch of the same bolt carriers groups.
I'm trying to contact Rainier Arms but after 2 weeks and 4 inquiries using their contact form page I haven't gotten a response. I haven't called them yet because I prefer to go through email for the reasons of mainly documentation purposes, personal convenience, and their phone support coincides with my work hours. I'm throwing this out there just in-case this can "encourage" them to respond by email.
This is my first AR build and also the first time purchasing from them. I really like their design and policy for their own products. Sadly because of mostly the customer service experience, for now I'll be considering other products and stores first before them.
I'll update this thread based on any progress regarding this issue.
Below are two videos that I managed to capture during my trip to the range show the brass stuck in the bolt:
[youtube]https://www.youtube.com/watch?v=aYLKeDEHuJ4[/youtube]
[youtube]https://www.youtube.com/watch?v=8ja9gxR3cjI[/youtube]