What is the recommended method for attaching a haul line to a firearm? tie it to the sling. tie it to the barrel. tie it to the wrist of the stock. tie it to the trigger guard?

The answer would be tie it to the sling. 
This is to make sure it is empty and that you haul it up with the barrel pointing down. If by coincidental you let it down to quick and it smashes the ground check the barrel for mud or grass. Put a piece of black electric tape over the muzzle when hauling the rifle up or down from a standpoint. 

in this scenario it would be the consumer demand as most influential in making the decision. the band members need to figure out where and from whom they will make the most money, in other words who out of the two consumer groups - football fans or car drivers - will spend their money, who is more likely to contribute to their cause and buy what they are offering.

answer; knowledge,reason,and judgement;