Hello, I just recently purchased a used DPMS SASS Gen 1. The guy I bought it from said he hadn't put more than 80 rounds thru it. He warned me that it doesn't like to fire anything under 180gr. Very clean and in great shape. I took it to the range today to sight it in. He was right. It would cycle 180gr ammo all day. Any time I tried to fire anything lighter, it would fire the round, eject the empty case, but fail to chamber another round. This leads me to believe that the bolt isn't going back all the way. Does that sound correct? The buffer spring is very tight but I'm sure it has to be for this heavy round. I was using a Gen3 Magpul 20rd magazine. My question is this: AM I doomed to only be able to fire 180gr or heavier ammo? Is there an easy fix that anyone knows about? Can I buy a lighter weight buffer? Any advice would be greatly appreciated. Thanks in advance, -Breck