These days, do a web search for any particular caliber (i.e. “9mm ballistic tests”) and you will get page after page of results, both text and video. The methods for determining the effectiveness of various loads include things like water jugs and wet newspapers.
But for “gelatin junkies,” the “gold standard” is “officially calibrated” ballistic gelatin, usually with the “correct” number of layers of denim and/or cotton. The better ones include chronograph information, as well as “post-mortem” analysis of the gelatin blocks.
Ballistic gelatin tests can give a rough approximation of things like penetration, as well as expose issues like jacket separation. But, contrary to marketing claims, what they cannot tell you is which bullet design is “absolutely, positively, no doubt guaranteed to expand every single time” in an actual shooting event.
Testing is fine. My problem is that many shooters seem to have an almost religious reverence for gelatin block tests, as if nothing else matters. This was brought home quite clearly by a conversation I overheard in a local gun store just last week. Two young men were asking an employee of the store which ammo he recommended for a SIG Sauer P220 one of them had just purchased.
At first, the store clerk properly advised the gun owner to test fire whatever defensive ammo he ended up with to be sure that it functioned properly in his gun. Kudos—flawless functioning is absolutely non-negotiable.
The store employee even correctly noted that some pistols, especially older 1911 types, are only reliable with standard “ball” ammo. At that point, the friend of the customer said “No problem. If you have to use the full metal jacket stuff, it will do the job. It’s a 45, for Pete’s sake!”
It was then that the store clerk replied, “Well, that’s not really true. Bullet construction is far more important than caliber.” He then categorically asserted that “ballistic gelatin tests prove that the wound channels of a quality .380 hollow-point do more damage than .45 ball.”
My jaw dropped. Sure, I occasionally carry a 380, especially here in Florida, where shorts and a T-shirt are often my daily wardrobe choice. And of course I want good quality defensive ammo that functions perfectly. But I would never prefer my 380 (no matter what ammunition you give me) to a 45 with ball ammo, if I were facing a 200-pound human attacker or a wild hog (which Florida has in abundance).
A lifelong hunter and now-retired trauma surgeon who specialized in gunshot wounds once humorously quipped:
“Ballistic gelatin tests tell you exactly what a particular bullet will do when fired into…ballistic gelatin!”
However, he reminded me that “the human torso is composed of things like tough bone, such as the sternum and ribs; tissue of varying elasticity; blood; and even air [e.g. your lungs]. Now add in the varying factors like clothing, shots that have to penetrate a forearm held up defensively, etc. Ballistic gelatin takes none of this into account.”
He also confirmed that as many as half of hollow-point rounds he pulled out of patients failed to expand. So just be careful about extrapolating what happens in ballistic gelatin to what will happen in a real live human body.
Bottom line? Focus on shooting skills. Then carry any good quality hollow-point from a reputable manufacturer that functions in your gun.