Here's my first set of findings from the test I volunteered for. And they were exactly what I felt they would be.
Measurements:I took measurements at what I felt were the three critical places where I felt failure may occur,
if there was to be a barrel rupture.
120 Grains FFFFg Goex Blackpowder - Single Patch BallA1.) 1.58 B1.) 1.56 C1.) 1.566 D1.)1.556
A2.) 1.226 B2.) 1.229 C2.) 1.231 D2.)1.277
A3.) 1.135 B3.) 1.135 C3.) 1.138 D3.)1.138
80 Grains FFFFg Goex Blackpowder - Two Patch BallsA1.) 1.58 B1.) 1.56 C1.) 1.566 D1.)1.556
A2.) 1.226 B2.) 1.229 C2.) 1.231 D2.)1.277
A3.) 1.135 B3.) 1.135 C3.) 1.138 D3.)1.138
60 Grains FFFFg Goex Blackpowder - Three Patch BallsA1.) 1.58 B1.) 1.56 C1.) 1.566 D1.)1.556
A2.) 1.226 B2.) 1.229 C2.) 1.231 D2.)1.277
A3.) 1.135 B3.) 1.135 C3.) 1.138 D3.)1.138
Comments:Ignition was acheived by means of an Estes rocket igniter and a squib. In my video clips
you can see how the smaller charges had more recoil and smoke discharge as opposed to the
first charge of 120 grains and a single patch ball. I feel that medieval gonne makers
anticipated such pressures, hence the sub caliber powder chamber. Modern commercially made
blackpowder is glazed and not porous like homemade or powder of medieval times. The glaze,
while protecting the powder from the moisture of enviromental humidity, actually retards
the powder's rate of ignition when compacted. However, when powder is loose, the rate of
burn is multiplied and higher pressures are achieved. Overall, no ill effect occured or was
discovered from testing.
Photos:Tannenberg prepared for firing, ignition by means of squib and Estes rocket igniter.
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tan_1fs.jpg - Full size photo, unedited
Holes in 1/4" plywood from double ball, 80 grain charge.
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tan_2a.jpg - Resized cropped photo for web use
tan_2fs.jpg - Full size photo, unedited
Holes in 1/4" plywood from triple ball, 60 grain charge.
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tan_3a.jpg - Resized cropped photo for web use
tan_3fs.jpg - Full size photo, unedited
Holes in backstop from triple ball, 60 grain charge.
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tan_4a.jpg - Resized cropped photo for web use
tan_4fs.jpg - Full size photo, unedited
Tools of the day:
A: Tannenberg Gonne
B: 4Fg Blackpowder
C: Digital Caliper
D: Brass Hammer/Short Starter
E: Pre-lubed pillow ticking patch material
F: .69 Musket Balls
G: Powder Flask
H: Powder Measure
tan_5.jpg - Cropped to focus content
tan_5a.jpg - Resized cropped photo for web use
tan_5fs.jpg - Full size photo, unedited
Movies:tan.wmv - 120, 80, 60 grain Discharges in that order
tan_120.wmv - 120 grain Discharge
tan_80.wmv - 80 grain Discharge
tan_60.wmv - 60 grain Discharge
tan120.wmv - 120 grain Discharge with title and credits
tan80.wmv - 80 grain Discharge with title and credits
tan60.wmv - 60 grain Discharge with title and credits