Ageous - the data you show is compatible with the general run of velocities and muzzle energies published to date. Between factory loads and handloads covered in magazines there are many more bullet weights and styles, but the ballistics are, again, compatible with what you have shown.
I have been gathering as much material as I can on this round since its inception, and in fact, wrote one of the first articles on it, although it was simply an introduction to the caliber for collectors, and had no shooting data to speak of. At the time it was written, the only factory load available was the 300 Grain TMJ at 700 fps MV. (IAA Jounral #439, Sep/Oct 2004, pages 38-39). None of the articles I have seen to date have included any scholarly testing for penetration or expansion. Few of them have even touched on this subject. It is a shame that the International Wound Ballistics Association is now defunct, due I suppose to the age of all of the principals. It was one organization that did scientifically sound, scholarly testing of ammunition, and would certianly have tested the .50 G.I. had it been around at the time.
One article".50 G.I." appearing in the Shooting Times" March 2006 issue, pages 58 to 63, by David M. Fortier, makes some attempt at penetration and expansion tests:
"…I decided to have some fun by placing a heavy block of solid oak downrange and pounding it with Black Hills .45 ACP 230-grain JHP ammunition. I followed that up with one each of the five different .50 GI loads. Next, I very carefully split the piece of oak open, recovered the projectiles, and measured the depth of their penetration. Deepest penetration was obtained using Guncrafter Industrie’s 275-grain JHP factory load, which went in 3.0 inches. The .45 ACP load went 2.5 inches. The shallowest penetration was obtained with the 300-grain Speer TMJ, which went in 1.6 inches. Oak is tough
"The last round I fired was a 300-grain Speer Gold Dot, and I put it into a line of water containers to check bullet expansion. Unfortunately, it pounded through 28 inches of water and was not recovered. However, the hole it left in each container (.51 caliber) seems to indicate that the velocity was too low for reliable expansion. .....To actually check the terminal performance would require the .50GI to be properly tested in 10-percent ordnance gelatin under controlled and repeatable conditions."
Surprisingly, the water test is not as amateurish as it might sound, as it somewhat would simulate the “Fackler Water Box” which generally gives decent results when compared with the more expensive and harder to use 10% Ballistic Gelatin. Mr. Fortier carefully qualifies his results and tells the reader that the testing was not the most reliable type. I applaud his article.
Another article, by John Taffin in “Guns Magazine,” September 2005, pages 44 to 47, shows the “Taylor Knockout Rating” for various factory loads. Since the numbers of themselves are pretty meaningless, which even Taffin admits to, there is no sense repeating them all here. The factor takes into account bullet diameter as well as muzzle energy, and the .50 therefore performed as would be expected, with all loads producing a higher index number than did any of the .45 loads, although it was close between the lowest number obtained with a .50 load (300 grain bullet at 700fps) and the highest produced with a .45 ACP load (185 grains at 1,150fps - all loads tested with the .45 were with 185 grain bullets).
One thing you didn’t ask that is more important than any factor, since shot placement is everything with a pistol, is accuracy. All bullet weights at all velocities in all articles written, reprtedly performed with excellent accuracy, indicating that the .50GI cartridge design is one that produces inherently good accuracy.
Summary: Expansion seems to be poor with most any bullet weight or design, but no truly scholarly testing seems to have yet been done and published. The question is, is expansion a critical factor for self-defense with a bullet that begins life at .50 caliber?
Don’t know if this is of any help or interest, but it is the best I can do from the published material I have received.