What's up with the gas key(s?) and being staked and whatnot? Are there ARs out there that aren't "staked" properly?
More so in the past than today but it does happen.
Gas keys with poor staking may come loose and cause a gas leak at the key.
Gas keys that are staked with too much enthusiasm can have the head of the key screw break off, causing a gas leak.
You can DIY staking with a punch or buy a specific tool for staking.
Young Manufacturing makes a premiere BCG, they are not staked and their warranty is void if you do stake them. YM uses the correct sealant and torque numbers with quality hardware. No staking needed.