Sir, there is no 'American grain' weight. The pound weight consists of 7000 grains. The pound referred to is the Troy weight pound that replaced the earlier and lighter Tower pound of twelve ounces.
Quote -
Pound, unit of
avoirdupois weight, equal to 16 ounces, 7,000 grains, or 0.45359237
kg, and of
troy and
apothecaries’ weight, equal to 12 ounces, 5,760 grains, or 0.3732417216 kg. The Roman ancestor of the modern pound, the
libra, is the source of the abbreviation
lb. In
medieval England several derivations of the
libra vied for general acceptance. Among the earliest of these, the Tower pound, so called because its standard was kept in the Royal Mint in the
Tower of London, was applied to
precious metals and drugs and contained 5,400 grains, or 0.350 kg, whereas the mercantile pound contained 6,750 grains, or 0.437 kg. The
troy pound, believed to have originated in Troyes, France, superseded the lighter Tower pound in 1527 as the gold and silver standard. Increased trade with France led also to the adoption of the 16-ounce avoirdupois pound in the 16th century to replace the mercantile pound.
As an aside, I was not aware that the French used inches for bullets and grains for powder.
Also, this is a quote from ctc-castelnau site -
Quelle poudre et quelle charge :
Il existe 2 principales poudres : la PNF2 et la poudre Suisse N°1. Cette dernière est un peu plus chère mais très régulière en granulométrie et un peu plus puissante ce qui permet des charges plus légères. En outre la Suisse N°1 laisse moins de résidus. La charge de poudre dépend de l'arme et du tireur. En général entre
0.8 grammes et 1.3 grammes de poudre mais chaque arme à un dosage préférentiel qui donne les meilleurs résultats. C'est donc une alchimie, qui fait aussi le charme de la poudre noire, pour trouver le meilleur chargement en poudre et diamètre de balle pour optimiser les résultats. Pour débuter et sans balance de précision, il est possible de doser simplement en volume avec
une douille de 9mm qui, remplie, fait de l'ordre de
0.9 grammes de poudre.
No grains there, eh? Of any kind.
Certainly, my experience of shooting French-made rifles - I began my shooting career on school trips to France and Switzerland from 1962 onwards - like Lebel, Gras, MAS, FAMS et al, makes no mention of inches or grains - millimetres, grams and metres/sec seem to be used to denote ammunition diameters, weights and velocity. I've obviously overlooked something here in my last sixty years of shooting.
