hey guys went to the range and put about 300 rounds through my ar-15 rifle. cleaned it as usual and assembled it like i have down a hundred times before. but now every time i pull the charging handle on my gun i some how make the buffer spring and buffer retain eject from its position. The spring and buffer now star to rattle through out the gun. Every time i start to break down the gun i find the spring inside the hand grip near the trigger and my buffer tube right near it. I cant figure out why all of a sudden the buffer spring and buffer retain are not staying in position.