I made a wetpack-test with hunting bullets I bought a few weeks ago to see how and if they perform. Wetpack means a box filled with soaking wet newspaper to simulate flesh and its by many considered to be more accurate in simulating flesh than ballistic gel.
Anyway, the pack was about 25cm thick, shot it with an 8x57 200 grain bullet at about 2500 fps or a tad under 800 meters a second. The bullet used was a softpoint flatbase hunting bullet, tombac jacket. Which is typically used for medium to large game. (European red deer, moose, elk) Unfortunately I could no recover the expanded bullet because its deeply embedded in a large log which I used as backstop.
Pics:
Entry. (I didn't even realize that there were kids on the top cover of the newspaper till I uploaded the pic. Bummer. *shrugs*)
5 centimeters in the wetpack the bullet started to expand:
The ''wound channel'' 2/3 into the pack, approx two fingers wide.
The exit after passing through ~ 25 centimeters of wet newspaper, creating a tennis ball sized hole. It really started to expand a lot in the last 7-10 centimeters.
Results:
Weight retention: the bullet didn't lose any material on its way through the wet pack.
Expansion: the bullet needed 5 centimeters before it started to expand. It expanded in two stages, first moderate expansion after 5 centimeters and about 2/3 into the pack it suddenly started to expand wildly Also the sharp edges of the deforming bullets jacket ''cut'' through the medium like a couple of razors. The wound channel looks smaller than it actually is because the paper around the channel expanded somewhat.
A tennis ball sized exit hole without even having hit any bones is nothing to sneeze at.