Buy features, not Brands. A good bolt carrier is the issue full auto M16 in at least military specification, at a minimum. Add surface treatments for extra protection. The gas key screws should be sufficiently staked to prevent loosening, the bolt MPI inspected, and it's good enough for combat. Literally.
More than that is for any specific reason the owner might choose, but "extra" reliability won't happen if a poor grade of ammo is constantly shot. The system is designed for full power military NATO ammo, not cheap bulk or rejected spec. Those cause far more stoppages than some want to believe.
That also goes to the charging handle. Milspec gets the job done, and has with very little change for over 45 years. If quality ammo is getting used, then the magazine is shot until it's empty, the bolt holds back, the operator changes mags, slaps the hold open button, the bolt chambers, and the rifle is back into battery. The charging handle only gets used to chamber the first round "in the wire" where it's being prepared to shoot.
Where the interest in uber grade handles comes from is competition shooting on 3Gun courses where a split second in elapsed time handling a malfunction under duress might drop someone in the standings. And that is who the handles are marketed to - none are issue, other countries using the AR15 haven't specified one they need, it's largely a matter of making something that will sell, not something that has demonstrated any critical need.
Build it and shoot it, then you discover any shortcoming that might come up for your special situation. But it does take shooting it to discover, not the marketing agenda or ego trolling that insists one specific type is required or you need to turn in your man card.
Over 7 million M16's and variants, over 20 million users since it was introduced, and the harsh reality is that ammo, mags, and operator error are the top three problems, not the gun.
