Staking a gas key screw that had been stretched too much (due to high torque levels) is known to sheer the screw at the thread root. The original design called for a sealant (hi temp aviation grade) and higher torque level. There are a few companies that build the carriers correct (sealant, higher torque values, and no staking) and they do not get failures nor leakage.
A little less torque and the staking is required because the threaded fastener has not differentially stretched which does in fact create a lock. Just think about all those cylinder heads out there with sealant, no thread locker and no staking. Threaded fastener technology has been well established for years, but most in the firearms industry are not up to date on it, for a variety of reasons, but that does not make the technology wrong.