Not to sound like a fanboy, but I had one of the first 2nd gen rfbs and the gas system was horrible. 40+ and still locking back. So kt emailed me a label and I shipped it off. I just got it back and wow!!!! I havent shot it yet but here is a list of upgrades for anyone with a smilair problem or if u r sendng yours in for service. 1. Upgraded bolt, (my daughter said it must be made of solid gold!) 2. Beefier extractors. 3. Reworked and polished feed ramps and lips. 4. Honed chamber. 5. A completely new style of piston and tube! I know it sux having malfunctions on a brand new weapon but Andrew not only attacted the gas issue, he upgraded everything he could. I am impressed once more by kt. Hopefully all new rfb's are leaving florida with these new upgrades. I write this for anyone having issues or are sending their rifle in for repairs. Use this list to your advantage. I cant wait till friday so i can put 100 rounds of DAG through it. I will post results.