Pretty much like the cavity of other  flat point, non-expanding bullet. That was not the focus of the test, but to compare depth of penetration. A customer from California had called, and complained about 155 X-bullet penetration performance in Lead-free, CA, so I tested the listed bullets for comparison.

Gentleman-

I worked for CEB when we developed these bullets, and was in charge of all reloading, expansion, penetration, and accuracy testing. I also recommended all bullet weights for every caliber, including the solids.

Testing with the 10mm was very impressive. Shooting into Clear Ballistic Gel, I received the following results, from a stock Glock 20:

1.  120 HG Raptor- blades went 6+ inches,  and the Blunt Trauma Base, around 16". These are meant for personal defense.

2.  155 Barnes X- penetrated around 18" if I remember correctly.

3.  150 HG Raptor- blades same distance as the 120 Raptor, but the base did 24", as they are meant for hunting.

4.  200 Hornady XTP at full power, expanded nicely, and penetrated 20"

5.  The 190 HG Solid...Was loaded to around 1,050 fps. To be sure, I lined up three, 17" blocks of  Clear Ballistic Gel,  AND placed a foot-long section of 2x6 pine, flat against the far end of the last gel block. This was all I could fit on top of the concrete bench I was shooting across. The 2x6 barely stayed in place, held mostly by the "stickyness" of the gel.

At the shot, the 2x6 fell off the end, because even the last 17" block "jiggled" at the shot. So I walk past the 3 blocks, stepping to the far side of the table to pick up the fallen 2x6...and found it to have a quarter-inch deep dent in the face, mirroring the nose of the bullet, which was against the last gel block!

Stunned, I turned to see at my face level, at the exit end of that last block, and saw the 190 HG Solid was sticking half-way out the block!!! If it hadn't been for the 2x6, it would have exited 51" of Clear Ballistic Gel!

And remember, this was at only 1,050 fps...so no need to worry about thinking you need to get too much more speed with this bullet!

And yes, because they are longer than conventional bullets, you need to use a lighter charge weight than you would with cast or jacketed bullets, AND faster burning powders, to be abke to get enough propellant energy in the case.

Best regards, Alasken
PS- when the owner was going whitetail hunting, I loaded up 150 gr. HG Raptors to almost 2,000 fps in his Super 14 Contender .44 Magnum, using Blue Dot powder.  At 104 yards, all four blades made it to the far side on a broadside shot, and the Blunt Trauma Base exited!  They penetrate all out of proportion to their "less than traditional" weights.  Good shooting!