That’s actually a good question

In theory: it might improve accuracy

In practice: it’s hard to really say. In this article, the author found some small improvements in his grouping, but couldn’t say with any certainty that it helped significantly

Only 3 out of 9 properly mushroomed

The tool used was “The Cavity Maker” by Ron Allard Enterprise

http://www.thegunmag.com/hollowpointing-22lr-is-it-practical-does-it-matter/

It really boils down to how much time and ammo you want to use up for experimentation