The size of the bore.
Size of bore, size of ammuntion
Size of the bore.
Diameter
Which of the following needles has the widest lumen?
Size of the bore. 12 gauge is bigger.
25 gauge is the size of the needle not the syringe. they are measured in cc's
Refers to shotgun bore size. Specifically, it refers to the number of lead balls of that bore size that it takes to make one pound. A twenty gauge takes 20 balls to the pound where a 12 gauge takes 12 balls.
No - the two have no relationship to each other at all.
Butterfly needles
21 gauge
This is a shotgun with an internal barrel diameter (called the "bore) of approximately .410" which shoots a shell which is about .410" in diameter. It is the only shotgun shell size that uses this convention. A 12 gauge shotgun, for example, does not have a bore of "12". A 20 gauge shotgun has a smaller bore than a 12 gauge and a 10 gauge has a bigger bore than a 12. Gauge size is based on the number of lead balls of the bore diameter which are required to make a pound (16 ounces). 10 balls, 12 balls, or 20 balls.