Hornady 115 grain Critical Defense is a reasonable choice. It functioned perfectly in initial tests with my son's 43. It shoots to the same point of impact as all standard 9mm 115 grain FMJ loads for practice. That 43 has about 1200 rounds through it testing the Hornady load and FMJ practice.
I have not screwed him up jumping weights and power levels. We adjusted the sight for a windage zero with the 115 Hornady. All 115 FMJ ball goes to the same place through 25 yards. He embarrasses me since at 25 yards he keeps all hits on IPSC "A" plates whereas the olde mano, weak, damaged, and of bifocals sometimes misses with much bigger guns. Getting old isn't for sissies.
The lighter bullet has a reasonable 9mm recoil and shoots to elevation zero also with the factory sights.