musket ball

I was in a old school built in the '40s and the field had been hit by metal detectors hard. In the field I got no good signals. I normally do not dig zinc signals but I really had really good feeling about this one. I figured "What the heck, i'll dig it" Then at 6" the object was out of the...

Found these 2 musket balls in my backyard in very close proximity. They are about the width of a dime, maybe slightly more. One of the pics below shows them with my other finds to provide some scale. Is there any way to approximate the date on these? I know the British camped overnight and...