See, you have a coupler. Then you pick your barrel, and use it or nest it (Put it inside a barrel that fits in the barrel. In this case, 1/2" PVC. Then put your dart in the back of the barrel, the dart pointing to the front, put the end the dart is in in the coupler, and shoot. Then remove the barrel, and continue.
Using the SCH80 pvc stub should get better ranges, as there's less space for the air to go into before it reaches the dart, resulting in higher pressure behind the dart. I would have used it, but the sch80 pvc was all the way downstairs, and I was just that damned lazy.
~ompa
Then how come you got un-damned-lazy when it was time for the barrel?