109 loads of popular self-defense pistol calibers (.380 Auto, 9mm, .40 S&W, .45 ACP) through a 4-layer barrier into ballistics gel. It’s just a portion of the full FBI testing protocol, but it’s still some good information across a lot of brands of ammo. Because no — all ammunition is not the same. They make a good point about this when it comes to switching calibers: that your favorite brand in 9mm may not perform the same in .45 ACP. It’s worth knowing and testing — and AmmoToGo did a lot of testing for you.
That said, this is just one data set. There are others out there that have done testing of ammo. Whatever you might be researching, I encourage you to seek out as much information as possible to make the most informed decision possible.
Disclosure: I heard about this test via a direct email from AmmoToGo. I received nothing in exchange for posting it — I posted it simply because I think it’s good and useful information worth sharing. I have been a customer of AmmoToGo for some time, and for many years they’ve been a go-to source for me because they have great selection and sometimes carry hard-to-find stuff that no one else stocks. Again, I’m sharing this because it’s useful.