I had a temp issue as well meaning my first run the temps came up real fast and it was HARD to get them down. The next run, in my chimney I put about 5 or 6 coals and lit them. The temps came up real slow and I was able to hit target temp on the first try and there she said save a minor valve adjustment here and there.
Nice looking barrel by the way!
If I could I would. If I don't, it's because I am to lazy!