13-3.7 Smokeless propellants intended for personal use in quantities not exceeding 20 lb (9.1 kg) shall be permitted to be stored in original containers in residences. Quantities exceeding 20 lb (9.1 kg), but not exceeding 50 lb (22.7 kg), shall be permitted to be stored in residences where kept in a wooden box or cabinet having walls of at least 1 in. (25.4 mm) nominal thickness.
13-3.8 Not more than 50 lb (22.7 kg) of smokeless propellants, in containers of 1 lb (0.45 kg) maximum capacity, shall be displayed in commercial establishments.
13-3.9 Commercial stocks of smokeless propellants shall be stored as follows:
(1) Quantities exceeding 50 lb (22.7 kg), but not exceeding 100 lb (45.4 kg), shall be stored in portable wooden boxes having walls of at least 1 in. (25.4 mm) thickness.
(2) Quantities exceeding 100 lb (45.4 kg), but not exceeding 800 lb (363 kg), shall be stored in nonportable storage cabinets having walls of at least 1 in (25.4 mm) thickness. Not more than 400 lb (181 kg) shall be permitted to be stored in any one cabinet, and cabinets shall be separated by a distance of at least 25 ft (7.63 m) or by a fire partition having a fire resistance of at least 1 hour.
That’s about smokeless powder. IIRC smokeless powder is what one uses in reloading. The article states he had 300# of black powder - quite a bit more flammable. They’re lucky they didn’t blow the place up if they were using jaws of life on a safe full of that stuff.
Mrs. AV
So, if he had the powder in safes, he could have multiples of 400# stocks within the law...of smokeless.