Timing a Gas Gun

I was reading the other day about Gas Operated Guns, (ARs), and timing. I know zip about building an AR or the science. Do any of you have any experience with an AR type and malfunctions caused by a gas timing issue?

For example dropped primers or failure to extract.

Failure to extract has always been either a weak extractor spring or a high pressure load for me.

http://www.majorpandemic.com/2013/06...-ar-build.html

I've built a few now. I have yet to have any issues with any of them. I doubt I am lucky, just that the parts are so consistent and standardized, little can go wrong. They are essentially plug and play and very easy to understand. With ARs, you either have too much gas or too little, which can be corrected in multiple ways, and easy to diagnose. Like I said, I have had no issues with any of them. I did have a problem with one cycling ammo I had loaded myself. It was a 20" barreled upper. I finally figured out that the 4198 powder I used was not suitable and swapped to another type, and all was well.

They are fun and addictive.