Sabres do use standard AR components. I don't have another lower or BCG to try or compare to, but it's a good idea.

I'm not certain fp protusion is good yet. Trying to measure that with calipers felt like I needed more hands to make sure everything was in place, and I got a wide range of of numbers when I repeated the process. Most were in spec, but I still don't really trust it. But I should have this tool in a couple days, so I'll get a proper measurement: https://www.creedmoorsports.com/prod...r_sports_brand