I just did my first smoke with my new WSM this weekend. It was also my first time using charcoal instead of gas.
Anyway, when I went to pick up charcoal Royal Oak Plus was $4 per 20# bag cheaper than Kingsford and I couldn't resist saving a few bucks.
Things seemed fine until I assembled the WSM. The temp dropped from 350 F, at 225 F I put the meat on but the temp continued dropping. I had trouble keeping the temp UP for the remainder of the cook.
Every hour or so I had to open the access door for up to 20 minutes to allow the coals to revive. Actually, I dangled it by a paper clip from the lid lip leaving about a 2" gap at the bottom of the access door instead of wide open. But I know the coals were dying because there was no smoke from the wood chunks until the coals came back to life.
Gentle prodding and stirring did not seem to help much, all vents were wide open, I did use the charcoal grate and chamber correctly I think.
Perhaps the charcoal was the problem. Is there such a thing as a bad or wet bag of charcoal?
I am going to try Kingsford this weekend. If it works better I will use up the Royal Oak for charcoal grilling, maybe some burgers.
Hope you have better luck with the Royal Oak than I, but being a beginner maybe it was my fault.