Welcome to the obsession ccarp!
7 gar in under an hour on your first outing? Nice job!
Gar can be tough to nail since they are skinny and their armored scales can deflect an arrow that might pierce a carp.

Mark is right on track. In my experience, most shots are within 30 feet, and you'll be surprised at the number of point blank shots you get, with most of those fish taking you by surprise seeming to appear from nowhere. Then you get a good laugh now and then when you bury the arrow in the bottom right next to the fish.

I do have extra line on both my bows (I think 30 yards) for the occassional long shot at a big fish, but mainly have it as insurance in case I have to cut the line due to a stuck arrow. It doesn't happen very often where I fish, but when it does, having the extra line keeps me in the game without having to reload with new line right away

Have fun.