Originally Posted by UnderNewOwnership
Dunno, never heard or read about one. Gas rams are a relatively new technology; they've only started to become widespread in the last two years or so. I suspect there still aren't enough of them on the market, and those which are haven't failed in any notable quantity yet.
Theoben in the UK have been making them since the late 80's. From memory the Weihrauch HW90 was a new design air rifle that had a gas ram in it from design stage. That it was in the early 90's.