The diameter of the larger circle (taken from the bottoms of the groves) is the Groove Diameter. It is the largest round thing you could pass through the barrel, without having to miss-shape it to make it fit.

The diameter of the smaller circle (measured from the tops of the lands) is the Bore Diameter. 30-calibre rifle is 30/ 100 of an inch, and that of a. In guns that have rifled barrels, e.g., rifles, pistols, machine guns, etc.The diameter of the bore is termed the calibre. While most other weapons are classed in mm. This designation still exists in the present day, when referring to shotguns (e.g. Long Answer: In the medieval period, the inner diameter of a barrel was frequently referred to as the bore (or gauge) of the weapon, and different weapons were classified by their bore size. Short Answer: Bore, in weaponry, is the interior of the barrel of a gun or firearm. 308вЂіДЄn AK-47 fires a bullet having a diameter of. though for technical purposes, thousandths of an inch are also given.ДЄn M1 Garand fires a bullet having a diameter of. In inches, Caliber, as a standard of measure, is given in tenths of an inch. Bullets are also measured as inches to like a 5.56x45mm could also be called a.

It can be measured in milimeters as in 7.62x39mm would be 7.62 milimeters across (diameter) and 39 milimers tall (length). Long Answer: The caliber is the size of the bullet. Short answer: Width of the bullet determines its caliber. I think this post will tell you all you need to know about both the things, and clear all your doubts. Also, I was asked the same question in 14 SSB Allahabad and I wish I would have known all this at that time. I chose this topic because I have met people who have confusions about what вЂњcaliberвЂќ and вЂњboreвЂќ are.

Higher calibre