The term "40 cal" typically refers to a .40 caliber muzzleloader, which has a bore diameter of approximately 0.40 inches (10.16 mm). The actual land diameter can vary slightly depending on the specific design of the muzzleloader, but it generally ranges from about 0.395 to 0.400 inches. This measurement refers to the raised areas (lands) in the rifling of the barrel, which grip the projectile as it is fired.
You do a diameter circle!!
It is half of the diameter or radius = diameter/2
The cord of a circle that contains the center of that circle is a diameter of that circle.
The diameter is the measurement of a line that goes right through a circle, through the centre point. In cases where we have a ring or some other such object with multiple circles, we would have an external diameter and an internal diameter. The internal diameter is the diameter of the inner circle. The external diameter is the diameter of the outer circle.
Radius = Diameter/2 Diameter = 2* Radius
0.05 in
Legally, no.
50-500 usd
They are called muzzleloaders simply because the powder and bullet are loaded from the muzzle end of the gun, Here is a page from WIKIpedia that may help answer.http://en.wikipedia.org/wiki/Muzzleloader
100-365 USD
100-700 USD or so
100-440 or so
Recommend you ask a gunsmith for assistance.
Personal preference is the biggest factor.
the groove
Yes
No