How does this compare to actual ballistic gelatin, and are you calibrating it? If not, seems like a whole lot of work that can't be compared to testing done with the real deal on a one to one basis.
No calibrating. The blocks are 9-10% by direct math (110.7oz water per 10.9oz gelatin, which is 10.9/121.6). They are all made the same. Not 100% sure why I got to 9%, I think I read that some of the water will evaporate slightly in the process thus increasing the %gelatin by weight.
Any variance from calibrated FBI spec won't really matter here as I am not comparing to any calibrated results that others have done. The temps of all 6 blocks will be held nearly the same as I transport them from fridge to location, and then used.
Let me say it via analogy. If my digital caliper is not accurate but precise, I can still make things fit even though the real measurement is off from calibration. Being off by 0.001" on everything is only an issue when relaying a measured # to someone else, or when the math is directly proportional to dimension/strength (like wheel bearing diameters, etc). With my gel blocks, they may not be accurate but the are all the same.
Another analogy, if my test target was only a gallon of water, it doesnt really matter if there's a spec temp to shoot a gal of water, as long as all the gal's are same temp when used.
Should I also be testing the denim to make sure it's truly 14oz denim? I think not, not for this testing. I cut all the denim from same yardage in same direction, so even if its 12oz denim it doesnt really matter, the denim is all the same.
I cannot think of any offset from FBI spec that would make comparing the OEM round vs the filled ones be invalid. If the OEM one expand to 0.625" but a filled one expands to 0.750" then i'll take it the filled one expanded better.