We'll size a parachute for my RCDP Flash-M, which weighs in at 17.5 pounds with 75/6400 case, or 7.955 kg.

We can find the descent velocity, given the chute diameter, by rearranging the equation to get:

v = sqrt((8 m g) / (p r Cd^{2}))

Just some calculations I did out of curiosity since BP Charges were a popular topic of discussion lately.

1 milliliter (ml) = 1 Cubic centimeter (cm3) = 1 gram (water) or 1.0441 grams (Black Powder)

Dr Rocket Motor Fwd Closure BP Charge Wells (if completely full)

29 mm is 1.43 cm3 (ml) (grams more or less)

38 mm is 1.61 cm3 (ml) (grams more or less)

54 mm is 2.94 cm3 (ml) (grams more or less)

29 mm and 38 mm motors have a funnel shaped taper into the hole. Volume and therefore grams is based on the average depth between the shallow part at the edge and the deep part at the middle.

54 mm motors have a flat well.

CTI apparently are all 1.3 g

*courtesy of Stan Hemphill*