Batch 2017-batch-01

16 grains of 54mm using sorbitol, intended to be 4 reloads for the longest 54mm snap-ring case currently in our possession, and/or some mix of lesser loads. Grain length 76mm with 2mm spacing per grain, so we'll make the casting tubes 78mm long. Delrin coring rods of 0.5" diameter.

We'll mix and pour 4 grains at a time to make the material handling easier with our available triple-beam balance. Formula for a batch size of 875g:

• 65% KNO3, 568.75g, taken from the big bucket this time
• 35% Sorbitol, 306.25g
• 1% red iron oxide, 8.75g, added after melt
• 12 drops Polystep-B1, added before pour using eye dropper

This formula is completely fluid with 225F indicated on the Presto Multicooker, but viscosity is noticeabley lower making for easier pouring at 250-275F.

These grains were cast on 15-17 May 2017.

Liner should be cut to 13.25" long for a 4-grain reload.

Results

• Grain 1, 176.1g gross, ?g net
• Grain 2, 187.8g gross, ?g net
• Grain 3, 187.6g gross, ?g net

• Grain 4, 185.8g gross, ?g net

• Grain 5, 187.9g gross, ?g net

• Grain 6, 188.3g gross, ?g net
• Grain 7, 186.7g gross, ?g net

• Grain 8, 181.3g gross, ?g net

• Grain 9, 191.0g gross, ?g net

• Grain 10, 190.3g gross, ?g net
• Grain 11, 189.2g gross, ?g net

• Grain 12, didn't weigh, burned in open air as a test grain

• Grain 13, 184.5g gross, ?g net

• Grain 14, 188.6g gross, ?g net
• Grain 15, 186.9g gross, ?g net
• Grain 16, 189.1g gross, ?g net

With a 13.250" liner, 8.9mm nozzle throat, buna-n o-rings, simulation says this makes a 39% J-597, 1050 Ns, with about a 1.5 sec burn