# Batch 2017-batch-04 # 4 grains of 29mm intended to be a reloads for the second-longest GMA 29mm snap-ring case, *and* 6 grains of 54mm intended to be 2 3-grain reloads, all in one sorbitol melt. 29mm grain length 45mm with 1mm spacing per grain, so we'll make the casting tubes 46mm long. Delrin coring rods of 5/16" diameter. 54mm grain length 76mm with 2mm spacing per grain, so we'll make the casting tubes 78mm long. Delrin coring rods of 1/2" diameter. Formula for a batch size of 1kg: * 65% KNO3, 650g, taken from the big bucket * 35% Sorbitol, 350g * 1% RIO, 10.0g * PolyStep B1, 15 drops With left-overs from batch-01, this was enough for all but two of the 29mm grains. We added enough materials for another 100g and were able to finish up with a bit left over. Presto Multicooker operated at 275F indicated. These grains were cast on 1 June 2017. Simulation says:
29mm 4-grain Sorbitol #14 | |||||
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Rating: | 99% G-180 | Max Pressure: | 6.47 MPa (939 psi) | ||
Total Impulse: | 159 Ns | Specific Impulse: | 133 s | ||
Max Thrust: | 228 N | Volume Loading: | 69% | ||
Average Thrust: | 180 N | Fuel Mass: | 122 g | ||