I'm guessing some type of rubber ring in there. And yeah, drilling would be much easier with the logs being different shapes. I'll have to give this a try once things warm up.
It's only illegal if you get caught.
If at first you don't succeed, use more lighter fluid
95% of Harley Davidsons ever made are still on the road... The other 5% made it home.
New Baltimore, Va '82 CB900c, 1980 CB985F/K 'Mutt"