Thanks very much. This is as I expected.

Here is one last question. Here in the U.S., I see 25 mm marine flares for sale, as well as 26.5 mm flares. The latter (ex-Czech army, I believe) look too long and perhaps too big in diameter to fit in a 1" (25.4 mm) bore flare pistol with a 4" barrel (but I recall reading someplace that the bore actually is more like 1-1/16", or just under 27 mm).

Anyway, does anyone reading this happen to know what currently-available marine flares are like to fit in this flare pistol? It is Birmingham proofed on the barrel for 1-1/2 tons per square inch. I assume all responsibility for blowing it up if I act on any opinion I read here!