The gun is great but I have a problem. I don't know a whole lot about guns. I pushed the pin to split it in half and the bolt and charging handle fell out. I put them back in and closed it up with the pin. After that, I pulled the charging handle back and it fell out. I know how to fix it but it will not split open when I pull the pin out. I just want to know what is wrong so I can get out to the range.