# Batch 2019.01.07 # 4 Terry-length Everclear grains for 54mm cases, with 0.625 inch cores, cast as two 6-inch-long double grains with 0.5" delrin coring rods, then cut, cored, and trimmed as necessary. The 54mm casting tube I'm using weighs 1.84g per inch. This was my first time mixing APCP propellant. Used the 4.5qt mixer and hand packed with no vacuum processing. The formula was taken from a pdf about everclear, modified by me to use PAPI as the curative. These grains were cast on 2019-01-07. ## Results ## The batch size was too small, so I couldn't fill the second casting tube, which left grain 4 short. * Grain 1, 2.990" long, 163.7g gross, 5.50g casting tube, 158.20g net propellant * Grain 2, 2.992" long, 163.8g gross, 5.51g casting tube, 158.29g net propellant * Grain 3, 2.976" long, 163.4g gross, 5.48g casting tube, 157.92g net propellant * Grain 4, 2.650" long, 146.1g gross, 5.52g casting tube, 140.58g net propellant The length of grain 4 is estimated by measuring the average lack of fill on the full-length 3" casting tube section. The mass per unit length was within 0.1g/inch, which seems awesome. Since these grains were processed with the ones from the next day, see that batch for masses lost in post processing, etc.