I agree, but they weren't so short on going from 7.62x25mm to 9x18mm. They new what they were doing, and in their tests, they found no difference in stopping power over the 7.62x25mm (smaller caliber but faster) and the 9x18mm (larger caliber but slower). Do you seriously believe they would have switched if it was so inferior?? Sorry, I'm a Mak fan and thought I'd speak up.
It was not inferior to TT. It just wasn't necessarily a better choice.
In the Soviet weapon procurement process, the two topmost and sometimes competing priorities were (a) the needs of the army and (b) standardization, low cost, ease of production, and ease of maintenance. The needs / wants of police were almost an afterthought. The Army got what it wanted, the state security services procured whatever weapons they wanted on an open market (e.g. they've bought large quantities of Lugers from Germany in the 1930s), and the police ("Militia") were given what was left over.
And the Army had always viewed handguns as officer's status symbol toys, not a real battlefield weapon. One of the main advantages of TT was that its round was interchangeable with submachine guns (which played a huge role in the Soviet battlefield tactics during WW2). However that round was a deep penetration round, that punched clear holes in targets, with a small wound channel and expending relatively little energy inside the body. An excellent round for a PPSh that had high rate of fire, not so great in a handgun. Also, TT was rather large and heavy.
During the war, the Soviets had really come to appreciate the power of 9x19mm Luger, the trophy German guns were very popular among the troops. After the war, the military decided to switch from submachine guns to assault rifles based on an upgraded German Kurtz round (what had become 7.62 x 39mm Kalashnikov). That meant that TT would no longer use an interchangeable standard round, and gave them an excuse to switch to a different pistol.
Initially they looked at using the Luger round. But two of the key requirements for the new gun were portability (neither the army officers nor the police wanted to carry a TT sized chunk of steel), low cost of production, and design for maximum reliability. And this meant a blowback pistol. The Soviets simply did not want to spend the money required to manufacture a more complex pistol, plus they didn't want to go through the effort required to work out quality control on a new design principle they've never produced before, all for a gun type that was a relatively low priority (as compared to AK). So blowback it was.
And you really don't want to use the 9x19 Luger in a blowback. It would be a very unpleasant shooting experience, with hard to do follow up shots. The 9x18mm Makarov round is about the most powerful that you can use in that kind of design.
So the Mak was kind of a compromise. It provided a somewhat better stopping power than TT, but not nearly as good as the Luger. And in the hands of very good shooters, TT was more deadly since it could easily penetrate many types of cover (e.g. cheap quality ballistic vests) that stopped Mak - but you needed a good shot placement to hit vital organs.
The Russians are very well aware of the shortcomings of Mak round, and had about a couple decades ago decided to switch to 9x19 Luger, but it's a long and drawn out process, mainly due to budget constraints and the huge quantities of perfectly functioning Makarovs still around.
Now, with all that, Mak is a very good round for SD, in my opinion. But then I also don't feel undergunned with .380ACP, and Mac is about halfway between it and Luger. But .380 is about the smaIlest I would go with.
My only issue with Mak is that none of the guns using this round are truly pocketable. Not as pocketable as my LCP. And if I have to carry a gun IWB or OWB, might as well go with a more powerful 9mm NATO.
That said, I would love to get me a Makarov one day.