Ammoland
They stated SOF M4A1s normally start to see accuracy degradation at around 6,000 rounds. But during testing of the mid-gas system, they’d hit 12,600 and still hadn’t seen any changes.
Although testing to 34,000 rounds isn’t yet complete, the conclusion is simple. Use of a mid-gas system significantly extends the life of the overall weapon system. It also offers increased performance over a carbine-length gas system.