I just bought a completely upper from live free armory in Florida. It is a 16 inch barrel with pistol length gas and a 1/7 twist.
The problem is when the bolt goes home the bolt sticks to the point to get it open I have to grab both sides of the charging handle and put the stock on my chest and pull as hard as I can I mean I'm 6'4 and it is hard for me to rack open. I have shot about 100 rounds of FMJ through it and it just doesn't like cast any ideas to help with the lock up?