There are remnants of the Civil War buried all around the country, and it’s not uncommon to find small musket balls.
However, it’s exceptionally rare to find entire weapons, especially complete rifles. YouTuber Aquachigger found a cache of Civil War artifacts while metal detecting in a shallow river. This included a number of cannon projectiles, horseshoes, and even a complete percussion rifle.
He also found fused cannon projectiles, which are now inert since the Civil War ended in 1865. Overall, this is one of the largest finds from this period that I have ever seen on film.
Note: This video is a little long, so skip to 23:40 to see all of the artifacts that were found.