What calibration means
Before a block is used for a real test, it has to be proven to behave like soft tissue. The industry does this with a single, repeatable check: fire a 0.177 inch steel BB into the block at 590 feet per second from 10 feet away and measure how deep it goes.
To pass, the BB has to stop between 2.95 and 3.74 inches. Less than that and the block is too dense. More and it is too soft. Either way it fails and cannot be trusted for a test. This is the FBI BB Calibration Spec, and it is the reference point the whole defensive-ammunition industry designs to.
Each block we ship comes with a calibration card confirming the batch is calibrated to FBI BB Calibration Specs. The result you need is documented, batch by batch.
10% and 20%
Our 10% blocks are calibrated to the FBI BB Calibration Specs, the standard for defensive handgun and most ammunition testing. Our 20% blocks are calibrated to the NATO BB Calibration Specs, used for higher-velocity and military-style work. The calibration specs match the recognized standards. If you are deciding which to test in, the 10 vs 20 guide breaks it down.
Why synthetic, not organic
The original protocol uses organic ordnance gelatin: mixed by weight, refrigerated, and used within about 20 minutes of leaving the cooler. It spoils, it needs a freezer and a temperature-controlled workflow, and it is fully opaque, so you have to cut the block apart to study the wound.
Our synthetic gel is calibrated to produce the same physical validation result without the organic process. No refrigeration, no spoilage, no 20-minute clock, and it is crystal clear, so the full wound profile is visible, photographable, and measurable without destroying the block.
We are calibrated to the FBI BB Calibration Specs. That is a calibration standard, not an endorsement. We say exactly that, and nothing more.
Calibrated, every batch.
Test in gel that ships with a calibration card confirming the spec.