Compared to terminal ballistic testing conducted in 10% concentration ordnance gelatin, terminal ballistic testing in water is a very simple process that greatly reduces the technical and logistic burdens of terminal ballistic testing while still producing scientifically valid, highly repeatable test data that is directly comparable to terminal ballistic test data obtained in shear-validated 10% ordnance gelatin and human soft tissues. At present, there are no other valid human soft tissue simulants other than 10% Type 250-A ordnance gelatin and water.
In an effort to provide legitimate test data for those who have elected to carry a short-barreled revolver (≤ 3 inches) for daily chores, I elected to test a round that has withstood the test of time (that's the ''vintage'' part of the test) remaining popular amongst those who desire—or at least hope for—projectile expansion from their snub-nose revolvers.
The following test data is presented without much commentary allowing for everyone/anyone to draw their own conclusions.
The test platform was a well-cared for, unmodified stainless steel Ruger SP-101 with a 3.0625-inch barrel with factory iron sights.
Impact velocity for each test projectile was measured with a Shooting-Chrony F-1 placed 10 feet in front of the test medium.
The test medium consisted of 12 water filled ˝-gallon paperboard cartons aligned in a row ahead of loose spun cotton batting in the event of projectile exit. Neither test projectile exited the row of paperboard cartons and both of them were recovered inside of a carton.
The test gun:
The test ammunition:
Date: 21st July 2021
Temperature: 89°F
Relative Humidity: 66%
Winchester .38 Special (MS) 158-grain LSWCHP (W38SPD)
Test Firearm: Ruger SP-101, unmodified
Barrel Length: 3.0625 inches
Barrier: None
Range: 21 feet
Test Medium: H
2O @ 82°F
Average Expanded Diameter: 0.6057 ± 0.0005 inch
Recovered Weight: 156.5 grains
Impact Velocity: 1,017 fps
Front:
Reverse:
Predictive Analysis:
Q-model
DoP: 13.27 inches
Wound Volume: 3.13 cubic inches
Wound Mass: 1.89 ounces
mTHOR model
DoP: 13.04 inches
Wound Volume: 3.08 cubic inches
Wound Mass: 1.85 ounces
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Date: 21st July 2021
Temperature: 89°F
Relative Humidity: 66%
Winchester .38 Special (MS) 158-grain LSWCHP (W38SPD)
Test Firearm: Ruger SP-101, unmodified
Barrel Length: 3.0625 inches
Barrier: 4 layers of 16-ounce cotton denim; IWBA standard barrier
Range: 21 feet
Test Medium: H
2O @ 82°F
Average Expanded Diameter: 0.4362 ± 0.0005 inch
Recovered Weight: 157.8 grains
Impact Velocity: 991.3 fps
Front:
Lateral:
Predictive Analysis:
Q-model
DoP: 27.24 inches
Wound Volume: 3.33 cubic inches
Wound Mass: 2.01 ounces
mTHOR model
DoP: 24.87 inches
Wound Volume: 3.04 cubic inches
Wound Mass: 1.83 ounces
It is interesting to note that, besides exhibiting mitigated expansion that resulted in significantly greater predicted penetration depth, the lead alloy was soft enough to capture the imprint of the denim fabric at impact.
DoP = maximum equivalent depth of penetration in 10% ordnance gelatin (or human soft tissue)
Wound Volume = total volume of the entire permanent channel
Wound Mass = total weight of tissue damaged/destroyed within the entire permanent channel