Instruct: Classify Amazon reviews into positive or negative sentiment
Query: worked great at first

I bought three of these guns because the first one was excellent at first. I framed a few houses with the first one and bought two more. then the firing pin bent on the first on after only a few months of work. I've always used Bostich nailers with years of service before any problems. I feel this gun is not reliable for production use. Now I buy Hitachi round head framers.