The mixture is 10%, by weight. The mentioned research shows that properly calibrated 10% ordinance gelatin is a reliable tissue simulant. Calibration of ballistic gelatin is verified by firing a .177 steel BB at 590 feet per second (fps), plus or minus 15 fps, into the gelatin, resulting in 8.5 centimeters (cm), plus or minus 1 cm, penetration (2.95" – 3.74"). During FBI tests, any gelatin blocks, which fail the calibration test, are discarded. Calibration results are not published due to the Pass/Fail nature of the test.

Fast & Easy Instructions for a 20 lb Block Weigh out exactly 2 lbs. of gelatin powder and place in a 1 gallon zip lock bag
Add 4 pounds of filtered tap water, temperature range 45 C (80 F)
Eliminate the air while sealing the bag quickly.
Gently mix the contents. NOTE: The contents of the bag will become very stiff within 10 minutes.
Refrigerate the bag if it will not be used within 2 hours. The shelf life of the bag in the refrigerator is 72 hours.
Bring at least 15 pounds of filtered water to a boil
Use a clean 5 gallon bucket with a lid Place the bucket without the lid in a scale. Note the weight or tare of the scale
Break up and place the contents of the bag in the clean 5 gallon bucket
Add 2.5 ml of de-foamer on top of the mix
Place the bucket on the scale and carefully add 14 pounds of boiling water into the bucket until you have exactly 20 pounds of mixture.
Remember to account for the weight of the bucket if the scale has not been tared. Gently stir the mixture for 30 seconds Place the lid on tight.
Gently stir for 30 seconds every 15 minutes for the first hour. Leave for 4 hours. Let stand for 2-4 hours
After cooling the mixture for 4 hours, slowly pour mixture into mold and place in refrigerator.
A household refrigerator will take approximately 72 hours for the block to set properly.

NOTE: Do not open refrigerator often. Doing so will bring the inside temperature down. A commercial refrigerator will cool the block faster. Allow curing for 36 hours (note: larger blocks require longer cure time. (e.g. an 80lb block requires 96 hours to cure)