Subject Guide
Mountain West
Malachite’s Big Hole
Gauge-Caliber Conversion Table:
Caliber is the decimal-inch diameter of the gun barrel. For example the land to land diameter of a 54 caliber rifle is 54/100's of an inch.
The gauge of a gun is the measurement of the bore of the gun in terms of the number of lead balls of the same diameter that would weigh a pound. For example a 20 gauge Northwest Trade gun would require balls of a size such that 20 balls would weigh one pound.
In the early 1800’s, a man was much more likely to refer to the bore diameter of his gun in terms of balls per pound than in gauge or caliber. "The rifle I use when I hunt large game shoots 30 balls per pound."
Gauge |
Caliber |
20 |
62 |
28 |
55 |
32 |
53 |
35 |
51 |
40 |
49 |
45 |
47 |