Batch 2017-batch-06

8 grains of 54mm using sorbitol, intended to be 2 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.

Formula for a batch size of 1750g:

• 65% KNO3, 1137.5g
• 35% Sorbitol, 612.5g
• 1% red iron oxide, 17.5g, added after melt
• 25 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 28 September 2017.

Results

Average casting tube weight 5.90g.

• Grain 1, 188g gross, ?g net
• Grain 2, 182g gross, ?g net
• Grain 3, 188g gross, ?g net

• Grain 4, 184g gross, ?g net

• Grain 5, 178g gross, ?g net

• Grain 6, 190g gross, ?g net
• Grain 7, 182g gross, ?g net
• Grain 8, 186g 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