An early smokeless propellant, so named because it was extruded and used in strands.

It is a (common) mistake to write about “the smell of cordite” in the context of modern ammunition. Cordite is not used in modern ammunition.

Cordite was used mainly in the United Kingdom, starting in 1889. It was used in the .303 British rifle cartridge until 1915. It was probably never used for handgun ammunition, and its use in small arms was completely phased out after World War II. It’s main use was in large weapons: tank guns, artillery, and naval guns. In the United States, its use was almost certainly limited to those large weapons. It has not been manufactured in this century.

At best, use of the word “cordite” should be limited to military settings involving the United Kingdom in the period between World War I and World War II.

I am not a historian, so my advice to writers would be to completely avoid use of the word “cordite” unless you are willing to put in the research time to verify the accuracy of its use in the specific period, region, and caliber.

Wikipedia: Cordite

I suppose one reason the phrase persists is that the smell of burnt gunpowder is not really something that can be described in words. [“not everything feels like something else.“] It smells burnt, but different from a wood fire or burnt matches. Undoubtedly, another reason is that so many authors have not smelled gunpowder. Also, the word “cordite” seems to lend credibility because it sounds authentic, even though it is not.