I don't know what to do...
Take up hunting. Hunting usually involves little actual shooting, so ammo cost is not a significant factor. Gas to get to a hunting spot can be, though. If you are in a rural area, though, maybe that is not a concern.
Still, you get exercise, fresh air, and the thrill of the hunt. Few things are most exciting than a life and death struggle. And you will typically not be the one that dies. Shooting animals out in the field is a whole different experience than shooting at a target range. It is far, far more challenging.
Also, try to think outside of the box when it comes to animals to shoot. Deer season, for example, is often only for a couple of weeks out of the year in many places, and you can only take one or two max deer. Waterfowl season is generally quite long, but not everyone is into being out at daybreak on a cold, wet winter day. But if you don't mind that, you can keep busy all winter.
There are a lot of nuisance animals that can be hunted in non-typical hunting seasons, sometimes even all year long.
This weekend my son and I are headed to Eastern Oregon to celebrate Father's Day together, and will hopefully return with our rifles quite bloodied. It is a great tradition to share with your kids, and pass down to future generations.
In fact, that would be another thing that one could do: introduce a teenager to the sport of shooting, and take them to the range with you.
One of my earliest shooting experiences was going to a range with the next door neighbor of my best friend. He was a WWII Veteran, and had a collection of M1 Carbines. And he also reloaded ammo. My friend and I had so much fun together shooting those M1's that day. The rifles had virtually no recoil, and were thus ideal for kids to shoot.
And here we were only 13. But those were different times.
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