Norma MRP is a flexible magnum powder that works well in cartridges that have a large case capacity relative to bore diameter. It has been well known for years for its outstanding performance in magnum cartridges.
Norma 201 is designed for calibers that have a small case capacity in relation to its bore size. These include the 45-70 and the 9.3x57 among others. 201 can also be used for lightweight, low velocity bullets in medium size cartridges like the 30-06 Springfield.
Norma 200 is the fastest burning powder in the Norma lineup. It is ideal for small cartridges like the 222 Remington and the 22 Hornet. 200 can also be used for lightweight, low velocity bullets in medium cartridges like the 308 Winchester.
Norma 203-B is a very flexible powder that can be used in 22-250 Remington to the 358 Norma Mag. 203-B is also well suited for cartridges like the 6mm Norma BR and the 308 Winchester shooting heavier bullets.
Norma 217 is a slow burning powder made for large magnum cartridges like the 338 Lapua Mag., 338 Norma Mag, and 30-378 Weatherby. It is also a good powder for loading large overbore magnums like 7mm Rem Mag and Ultra Mags. This powder like URP contains a lot of energy and is less sensitive to changes in temperature and moisture compared to other powders.