Tuesday, March 18, 2014

Cubic Inches (continued)

Too poor to paint.  Too proud to whitewash.  Test 1.0 on ERJ propellant, 64-point-05 Feet Per Second

Slow Pitch Softball, Anybody?


I became impatient. and wanted to see what ERJ Propellant t would do.

I loaded 100 grains, weighed on a balance scale.  I used Hornady 50 caliber, 385 grain Great Plains Maxi-bullets (#6620) as the pay load.  The launching platform is a CVA .50 caliber "Wolf"muzzle loader.

I measured 64 feet per second which is way below the 1400 fps or so that is my end-point.  A detectible hang-fire was observed.

The positive is that it combusted and generated enough pressure to expel the bullet.  8-)

Four potential theories for the gap.  Countermeasures are ways to prove/disprove theory.

1.) Powder not completely dry.
Countermeasure:  Continue to dry powder and try again in a week

2.) Cornstarch not charred completely enough.
Countermeasure: Make another batch from the beginning.  Char until no smoke is being generated.

3.) Granulation too coarse.
Countermeasure:  Sift powder to provide uniform granulation.  

4.) Formula non-optimal
Countermeasure: Investigate variation in formulation after eliminating 1-3.

The theories are listed in the order given because theories one and two are both consistent with the hang-fires.  Theory one requires the least effort to check out.

Theories one and three combine well and theory two is a stand-alone that can be pursued in parallel with (1 + 3).

There is little point if fiddling with formulation until I can get 500fps with no hang-fire.

To be continued

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