If it was a rifle ammo I would say that a different round hits a different spot at the target. You want to zero the scope with the round that you intend to use the most, and write down the corrections for other rounds that you have.
However handguns are far less accurate. I doubt that there is much difference between different rounds, considering that, reportedly, an average LEO cannot reliably hit a threat from five yards away. 1 MOA difference does not matter when the operator's error is in excess of 600 MOA.
I heard that the government claims lower cost, since hollow points are not entirely lead. However the cheapest rounds on the market are FMJ; hollow points are far more expensive, probably due to often complicated construction of the bullet.
Yet another theory says that the government does not want to bother with maintaining two stocks of ammo. That makes some sense; in my personal opinion that's the real reason.
However it is blatantly obvious to any observer that the country is quickly running out of other people's money. As soon as that happens all the ghettos go up in flames - and the suburbs won't be far behind. This Colossus has very fragile legs; just like the Shuttle, it works fine only when every piece of it is operating properly.
This is not entirely true.
The bullet weight has a substantial relationship to point of impact and sight adjustment. Essentially, the pistol is recoiling and the muzzle is rising while the bullet is still in the gun. Heavier bullets will shoot to a higher point of impact.
Practice should always be with the same weight bullets as service rounds.