I don't like most service calibers because they have been setup to fulfill a false standard. If you read Urey Patrick, FBI firearms expert and authored internal papers on recommending the 10MM for the FBI, his recommendation is the bare minimum is 12", with 18" of penetration ideal, or there abouts.
He makes the point over and over in his recommendations that under-penetration is what will get you killed.
I do see the merits of ammunition that penetrates only a foot, under ideal conditions. Crowded scenarios, cities, trailer parks, etc.
That said, I prefer not to sacrifice the penetration for expansion. Along with this sacrifice of penetration you have a bullet that dumps a huge percentage of its energy in the initial hit of the target. What if that initial penetration is an arm that is obstructing vital organs, because the person is shooting at me? Tests indicate that skin is difficult to penetrate on exit, and
requires the same amount of energy as is required to penetrate 4-6" of gelatin. In the arm shot scenario, in line with a vital organ, you now have seriously added to the penetration requirement. The bullet must enter the forearm, penetrate through it, how far determined by the angle of the shot, but generally it's going to be going from hand, down through the forearm, and then must expend 4-6" of gelatin energy to exit the arm. It is not unforeseeable that the bullet with 12-14" of penetration has used it's kenetic energy to penetrate, and exit the forearm. Upon hitting the chest
the bullet is already expanded, and has lost 90 percent of it's energy in the forearm, making deep penetration unlikely, and failure to penetrate the chest, and get to any vitals highly likely. Hopefully it takes that arm out of the fight, but it may not take the bad guy out of it. Seems to me a lot of arms got hit in the Platt shooting, and, the bad guys continued shooting, and killing.
I don't find these discussions as a general rule valuable, because factors we can't discuss should really be weighed heavily in your decision on what to carry. Location, situation, law, etc.
That said, as a general rule, I would go with Mr. Patrick's FBI recommendation and pick ammunition that penetrates ideally 18" in gelatin.
I might also suggest that to accomplish the goal, using a flat point, as near as possible, combined with a weight that limits penetration to the 18" range
requires a bit of research.
Almost all the gelatin work is on hollow points that generally never go deeper then 14". FMJ, the standard bullet weights, tend to penetrate in excess of the 18" desired range. A lighter bullet, with a more LFN style nose needs to be researched, and combined with proper velocity to achieve this goal.
I can't think of one FMJ/TC type bullet that is tailored to penetrate to 18".
The benefits of applying this approach to service calibers are
far cheaper ammunition, more practice, accurate, little sacrifice in wound channel, since the bullet velocity will be higher due to the lighter weight of the FMJ/TC, 100% expansion consistency.
I've settled on 260 grains at 800 fps, with a LFN style bullet. That load is tailored to my area, not yours. I use a .45 Colt.
My second shot speed and accuracy are considerably above average with this setup.
YMMV.
