Vihtavuori N133 Smokeless Powder - 1lb Can - Originally developed for the 5.56 Nato cartridge, Vihtavuori's N133 is a multipurpose rifle powder for centerfire .22 cartridges and PPC caliber cartridges. N133 is a tubular powder with grain dimensions of 1,1 mm length and 0,8 mm diameter. The burn rate is medium in the scale of Vihtavuori's rifle powders, and it works like a charm with .223 Remington. Lot-To-Lot Consistency Temperature Stable Decoppering Agent Clean Burning