Regional Government Sales Manager for Aimpoint, Inc. USA
Co-owner Hardwired Tactical Shooting (HiTS)
Wayne Dobbs is correct....as usual.
Facts matter...Feelings Can Lie
As a non-LEO, I skip the windshield glass test and simply look at the 4LD. And that's only because I find the results interesting. Basically, I too simply rely on Doc's advice (and price) in my selection. In other words, I try to buy the cheapest reasonably available load that Doc says is good, hope I never have to use it, but train to use it effectively.
Ok, Here is the Cliff Notes abbreviated version of the article.
Organic ballistic gelatin simulates soft tissue of the body, but it is not identical by any means.
Synthetic gel does not match organic gel in characteristics.
Ballistic gel of any type is only a comparative medium for assessing the performance differences between bullets and nothing more.
Ballistic gel tests provide comparisons of expansion and penetration as they are related. Deeper penetration with consistent expansion is generally a good SD round.
The FBI criteria are not perfect but they are the best available.
It's a very bad idea to disregard that windshield glass test for some of these reasons:
1. Do you ever carry a gun in a car for protection from carjackings, kidnap attempts, etc.?
2. Would you consider shooting through the car's glass structures to stop that type of assault?
3. Did you know that since ~2016, ALL the glass in a car is laminate glass exactly like windshields?
4. This test also gauges the ability of a load to defeat a hard barrier, like a bone. Bone is a barrier certain to be present at a defensive shooting, whether it's struck or not during the shooting.
5. The 4LD test is a gold standard, for sure, but it's more than interesting. It's a well thought out test to ascertain whether a load has robust performance, which is an engineering/scientific term for consistent performance across a range of demands.
6. The thought/hope/belief that your assailant will present you an unprotected frontal attitude is not well founded in actual events. They may start that way, but they likely won't remain so.
Use both events.
Regional Government Sales Manager for Aimpoint, Inc. USA
Co-owner Hardwired Tactical Shooting (HiTS)
I'm obviously not Doc, but IIRC he advised that the 147s lose less performance from short barrels than lighter bullets.
FWIW, I'm sticking with 124 +P HST, because I have a few boxes, it shoots to POA, and practice ammo and reloading bullets are cheaper. My shortest 9x19 barrel is 3.5" and it loses about 20 fps compared to the four-inch versions. IOW, not enough to worry about.