My friend had a delton AR 16". I have an identical model. A few months ago at the range, his bolt pretty much cracked and fell apart. The part of the bolt where the shell extractor is, just broke into about 3 pieces. This got me thinking about my bolt. So I opened up my AR, and it has a different bolt. It was the exact same model that he ordered but around a year earlier. Where as mine was purchased right at a month ago. Does anyone know of delton replacing their bolts? Or anything similar?