Originally Posted By: MadCowRacer
One bullet and the empty magazine would not lock the bolt back. I shot six shots, and only the first actually cycled the bolt. Is there a chart out there that has burn rates of powders? A one stop place rather than sifting through every manufacturer site.

Burn rate has nothing to do with it. Powders side by side on the chart will often exhibit different levels of reliability. You can load hotter for more gas, or drill the gas port for more gas flow. If you do the second you can often put an adjustable gas block on it and tune the gas to the load and broaden your operational envelope.

Even some factory ammo won't cycle AR's that run perfectly with other brands. If it is a new rifle often a couple hundred rounds will smooth things up and the issue goes away.


PS: Don't forget to try a different magazine as this will sometimes be an issue.