You found a nice camp-gilted buttons cleaned up nicely. The buck and ball looks 69 caliber. If that is the case, those three roundballs aside it are most likely 36 caliber rifle or pistol bullets. Generally, the buckshot associated with buck and ball cartridges will measure twenty-something millimeters (often 23-27 mm). I have found a few varying sizes on 69 cal. buck and ball combos that measure differently, but never over 30 mm's. Most of what I found date 1835-1842 and were dug in camps belonging to the US Dragoons; The Artillery and the Infantry. Good Luck with the camp--I look forward to seeing more of your posts.