Should cartridge colour denote bore?

Q: Why don’t cartridge makers stick 
to an internationally agreed colour code for different bore sizes as used to be the case (12-bore were red, 16-bore blue and 20-bore yellow)? Surely this would stop all of these dreadful accidents where people who mix cartridges double-load a 12-bore on top of a 20-bore that is stuck up the barrel.

It’s a shooting myth

A: It is one of those shooting myths that different bores of cartridge were always colour-coded to distinguish them. Eley used to load some of its 12-bores with cherry-red cases, its 16-bores with blue and its 20-bores in yellow, for example, and this has fuelled the myth that such 
a code existed in the first place.

The problem caused by a double load was recognised in the 1920s. I have an original Eley catalogue that mentions this problem along with a specially coloured cartridge case made to alert people to double loading. Its colour? Not yellow as you might think, but amethyst with black 
lines along the axis and the words 
“Eley 20 gauge” on it.
The fact is that makers use, and have used, many colours of card or plastic to market their cartridges. It boils down 
to marketing and being able to make 
their product stand out from others to boost sales.

The solution to the 12/20-bore double load lies not in case colouring but in vigilance. If you glance up the bore of your gun before every shot to check it is clear before loading another round, this can never happen.

Also, if you have both 12- and 20-bore shotguns, then only load with 12s from cartridges that you have taken from a belt. That way if you inadvertently put a 20-bore into the larger loop while filling the belt, it will fall out. This may seem like a bit of a fag.

Trust me when I tell you that it is infinitely less tedious than having the trauma of a gun failing and losing 
a couple of fingers when it does.