+so we can make density and burn rate measurements after cure. The excess
+weighed in at 17.9g after cure.
+
+* Grain 1, 2.980" long, 162.6g gross, 5.48g casting tube, 157.12g net
+* Grain 2, 2.970" long, 162.0g gross, 5.46g casting tube, 156.54g net
+* Grain 3, 3.010" long, 164.7g gross, 5.54g casting tube, 159.16g net
+* Grain 4, 2.995" long, 163.6g gross, 5.51g casting tube, 158.09g net
+
+The mass per unit length was within 0.1g/inch, which seems awesome.