I just bought a new upper from CBC industries and it fit a little loose on my bushmaster lower. The rock river upper I had on there fit firm with absolutely no play. I'm very new to the AR platform so any advice would be much appreciated. Thanks
There is simply that much variance between manufacturers, although one would think the higher ends names would be a bit better. I don't think CBC falls in this category.
In any event most people just dont worry about it, because it doesn't affect much. If it does annoy you though, this is this product for that problem:
Typically, Rock River Arms receivers fit very tight. They have for years. There is quite a variation in the fitment of other receivers on the market. Even though several companies may use the same forgings as some others, how they are machined and finished/coated makes the difference in fitment. As far as CBC Industries goes, I have no idea where they acquire their upper receivers or if they are finished when they get them or if they buy the forgings and do the machining and finishing themselves, which I doubt they do. Personally, I would never buy any upper assembly from CBC Industries. Most of their stuff is of unknown quality and origin. I hope that you have good luck with yours.