High quality product - Strike Industries AR-10 Flat Wire Spring

I’ve used several of these springs in different AR’s I’ve built. They’ve always worked great and reliably. I actually installed this latest one in an AR-15 9 mm pistol I built. I can’t say yet how well it works or if it will be too stiff for a 9 mm application but many people say that it’s best to use an AR-10 buffer spring in a 9 mm build, so I’ll have to see if it functions properly. I’m using a 6.5 oz. Buffer so I wanted a stiffer spring in it since I already had the buffer from another build.