Per Wikipedia:
Each D839 propellant (smokeless powder) grain used for full charges for this gun was 2 in (51 mm) long, 1 in (25 mm) in diameter and had seven perforations, each 0.060 in (1.5 mm) in diameter with a web thickness range of 0.193 to 0.197 in (4.9 to 5.0 mm) between the perforations and the grain diameter. A maximum charge consisted of six silk bags (hence the term "bag gun"), each filled with 110 lb (50 kg) of propellant.
Some confusion probably comes from the ignitor charge of black powder sewn into a red quilted layer on the end of the silk bags. Red end of bags were loaded facing the breech, firing cartridge set off black powder which in turn ignited main smokeless powder charge. There was maybe a half pound or less of black powder for every 110 pound bag.
Modern artillery propellant charges like the 155mm howitzer still use a few ounces of black powder as an igniter.
