Best Caliber to Minimize Over Penetration

[IDCG]

Hello Mas

A friend wants to purchase his first pistol for home self-defense, so I took him to the range to allow him to try different pistols I own.

He's narrowed his choice to either a G17 or G22. He actually prefers the 9mm, but is concerned that 9mm may be more prone to over penetration than a .40.

I believe as long as he uses a modern hollow point, the 9mm wouldn't be any more prone to over penetration than a .40.

Am I correct?

Thanks for sharing your experience with us!

Ira

[Mas Ayoob]

You're correct. Although caliber enters into it in terms of sectional density and its relation to penetration, it's much more about bullet design.

If your friend is particularly concerned with excessive penetration, a 115 grain 9mm JHP at 1300-1350 feet per second or a 135 grain .40 JHP at 1300 fps will each give about ten inches of penetration, and should be suitable to the performance profile he seems to be looking for.

Hope that helps,
Mas