Question 1

What is a grain (weight)?

Accepted Answer

A grain is 64.8 mg. Used in pharmacy and ammunition. 437.5 grains = 1 ounce. 7000 grains = 1 pound.

Question 2

Why are bullets measured in grains?

Accepted Answer

Historical convention from gunpowder era. Common bullet weights: 115 grain (9mm), 230 grain (.45 ACP).

Question 3

Is there a difference between mass and weight?

Accepted Answer

Yes! Mass (kg) is amount of matter, constant everywhere. Weight (newtons or pounds-force) is gravitational force on mass, varies by location.

Question 4

Why do jewelry and precious metals use different units?

Accepted Answer

Troy system (troy ounces, pennyweights) has been used for precious metals since the Middle Ages. 1 troy oz = 31.1g vs 1 regular oz = 28.35g.

gr to g Converter

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