I ran a firing line supervised by 5 active duty soldiers last weekend. I oversaw the firing of about 2,800 rounds through 6 AR's from 4 different manufacturers in about 3 hours. All of them were inspected, cleaned and PROPERLY lubricated prior to firing and periodically throughout. I called the two that choked and quit about 10 minutes before they did exactly that.
I love real-world experiences with AR-15 failures. Can you please be more specific - what brands, what round count, how they failed?