Nomenclature - Common Definitions

[smithy]

This is a topic thread to document interesting nomenclature related to firearms and other weaponry.

[smithy]

I will start things off with "drachm"

Drachm

A "drachm" (also spelled "drachma" in some contexts) has several meanings based on historical usage:

• As a Unit of Weight: In ancient Greece, a drachm was a unit of weight equivalent to about 66.5 grains or 4.3 grams .[/color] In the apothecaries' system, which was used in medicine, it equals one-eighth of an ounce apothecary (3.89 grams), symbolized by ℨ or ʒ. In the avoirdupois system, it was one-sixteenth of an ounce, or about 1.77 grams.

• As a Unit of Volume: In pharmaceutical contexts, a "fluid drachm" or "fluid dram" refers to a volume measure, equivalent to one-eighth of a fluid ounce.

Historical Context: Drachms were used from the Archaic period through to the Roman period in Greece, with variations in weight and value over time and by region. In the Hellenistic and Roman periods, drachms were used by various kingdoms and were sometimes gold.

Modern and Obsolete Usage: In modern contexts, especially in British English, "drachm" might be used as an alternative spelling for "dram," which can refer to both weight and volume measures in different systems. The term "drachm" in American English also refers to this historical weight or volume measure.

[adavis]

Lands

In the context of muzzleloaders, "lands" refer to the raised portions inside the barrel of a rifled firearm.

• Definition: Lands are the raised areas or ridges inside the barrel of a rifle or rifled muzzleloader. They run lengthwise, parallel to the barrel, and are separated by grooves (the lowered parts between the lands).

Purpose

• Rifling: The combination of lands and grooves forms the rifling of the barrel. Rifling imparts spin to the projectile (usually a bullet or ball), which stabilizes its flight, improving accuracy and range.

• Engagement: When a bullet or ball is fired, it engages with the lands, which cut into or deform the projectile, causing it to rotate around its longitudinal axis as it travels down the barrel.

• Number and Configuration: The number of lands and grooves can vary. Some common configurations include 3, 4, 5, 6, 7, or more lands, depending on the design and intended use of the firearm. For instance, traditional muzzleloaders might have fewer or an odd number of lands, like seven, for reasons related to manufacturing or performance. The pattern or twist rate of the rifling (how quickly the lands and grooves spiral around the bore) also affects how the bullet or ball spins and stabilizes.

Muzzleloader Specifics

• Traditional Rifles: Many traditional muzzleloaders, like flintlocks or caplocks, might have fewer lands and a slower twist rate compared to modern in-line muzzleloaders.

• Modern In-line Muzzleloaders: These often have more lands and a faster twist rate to accommodate modern bullet designs, like sabots or conical bullets, which require more spin for stabilization at longer ranges.

• Historical Context: The number of lands was often chosen based on manufacturing techniques, the type of projectile used (round balls vs. conical bullets), and the desired accuracy and range. For example, an odd number of lands could be advantageous in traditional manufacturing to ensure a flat surface for the cutting tool, as discussed in muzzleloading forums.