You find what appears to be a 3 foot tall modified barrel. It has 8 knobs around its base each with a slot going up the length. On one side it has two metal handles, the bottom of which has a lever, and a large leather strap. Inside the barrel you can see a canister filling the whole barrel with 8 holes just bigger than your thumb carved into it.
This barrel weighs 30 pounds, and has the property heavy. It can hold and fire up to 8 bolts before you need to reload. It is similar to a light crossbow except it has half the range (40/160 feet) and doesn’t have the loading property. It automatically rotates to the next barrel until it runs out of ammunition. You can reload up to two bolts as an action.