Home Forums Hunting & Shooting Ask The Gunwriters Hydrostatic Shock

When I was a youth reading and rereading every gun and hunting related magazine I could get my hands on I believed the way to kill a deer was to put a fast enough bullet into a deer that would expand and dump all it's energy without exiting ideally so there was maximum energy transfer. Now I read all this about how good Barnes bullets are and I wonder if all that was bunk. I've killed deer that died like they had been hit by lightening with an expanding bullet and I thought that might be why. On the other hand I've hit and killed others that acted like they didn't even feel the shot. Is hydrostatic shock real or a myth?

In the beginning (meaning in the days when Roy Weatherby started out) "hydrostatic shock" was claimed to push blood throughout an animal, like brake fluid being pushed throughout the brake system in a vehicle, which supposedly severely damaged all the organs from the heart to the brain. According to some advocates (including Roy) this meant it didn't matter where you hit an animal, because the sudden blood-pressure rise would kill it immediately,

Roy didn't have much experience shooting game at that point, and later, on his first African safari, found it didn't work nearly as neatly as he expected and claimed. Since then some have claimed that the way a "high velocity rifles bullet" explodes an apple, can of beans or even a gallon jug of water is evidence of hydrostatic shock. And there's no doubt high impact velocity does more damage than lower velocities with the same bullets.

But the hydrostatic shock theory as promoted by early high-velocity advocates is BS, primarily because internal organs of big game (which include the veins and arteries of the circulatory system) are far more flexible than brake lines, and vary far more in diameter. Which means that shooting even a deer in the butt with a super high-velocity bullet has no effect on the brain, or any other major organs.

The major factor in "killing power," however it's defined, is not the mythical hydrostatic shock, but how much damage a bullet does to vital organs, which is why fragmenting bullets often kill game quicker. But sometimes non-fragmenting bullets kill just as quickly, or at least drop them as quickly, especially if the bullets pass close to major nerve systems.

I'm sure most of us have had a common situation where they double lunged a deer and the deer went 75 yards and dropped. but we've also made the same shot and the deer fell in it's tracks instantly. If you don't hit the spine or the brain what causes this lights out effect sometimes?

Park your vehicle over there first. Easy.

I grew up with the exact same theory....until one day I hit a small buck with a ballistic tip from my .270 and the deer ran off. I finally found it in some bushes and it was hit fairly well. The range was about 25 yards and the deer should have dropped instantly.....

I decided that from that day forward, I wanted an exit hole to create a better blood trail to follow. I didn't dismiss the hydrostatic shock theory but was willing to sacrifice some of the bullet's energy to create an exit hole. That was 40 years back and since then have never regretted that decision. The hydrostatic shock theory has come up several times since then and always been dismissed as of little importance or non existent (even with good bullet placement.
Today I look for
1. Sufficient accuracy to yield good placement
2. A tough enough bullet to exit
3. cartridge with enough energy capability to force the exit....(most modern rifles are capable of that)
4. sufficient bench time to keep my shooting skills in reasonable shape

Bear in mind.....there is no bullet that will always exit.....even the Barnes that I like to shoot will not always exit.....nor will the Nosler Partition.....but your chances are better. It's been said thousands of times.....Placement is the key!
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