Originally Posted by avfc1982
Actually that's not what I am going to say! What I am going to say is due you really think that the pull of gravity on the barrel is equal to or greater than the weight of the moderator? Do the math!
The point of hanging the moderator on there is to show how a relatively small change in weight can have a significant change in the point of impact.
When the barrel is horizontal, the full force of gravity is acting upon it, pulling it down. When the barrel is tilted to full vertical, gravity is no longer bending it downwards and therefore pointing higher than expected.
Regarding the actual weights, the moderator weighs 165g and the barrel weighs 256g. So gravity is bending the barrel with or without moderator.