Good, to very good when one considers the cost.I've looked closer at the bca uppers. How is the quality? It's hard to believe a complete upper with a stainless barrel for just over $200!
What you USUALLY get, is a fully functional upper thats good but not fantastic in finish work. Watch for sharp edges. IMO these sell for about what a decent upper SHOULD cost. Your not buying name, or nice, your buying working.
Both of mine are fully functional (the .350 even feeds XTPs) and actually as well finished as any ive seen in the price range or a bit more. Accuracy with decent ammo has been very good.