Short Barrel Performance Loss
How Much Performance Do You Lose to a Short Barrel on Your Hunting Rifle?
Short barrels bother some hunters. They shouldn’t.
It’s true that short barrels usually cost you some velocity. A cartridge/bullet fired through a 24-inch tube will generate more speed than the same cartridge/bullet fired through a 22-inch tube, 18-inch tube or 16.5-inch tube. But is it enough to matter?
Not so far as the deer are concerned.
The thing about deer, elk, moose, bears, kudu, eland and tree squirrels is that they don’t know what hit them. Disrupt their cardio/pulmonary system or central nervous system and they’ll expire quickly if not immediately. They do not care if this was done by a bullet racing 3,400 fps, 2,400 fps, 1,400 fps or 400 fps. They don’t even care if it was a broadhead creeping along at a mere 250 fps. None of those are going to bounce off! That’s why poachers kill so many deer with 22 Long Rifles.
You see, speed doesn’t kill. Not even the energy contained in that speed kills. The knockout punch only counts when it connects with the central nervous system, and then — as the 22 Long Rifle has again and again proven — just a little goes a long, long way.
And that takes us back to tissue destruction, a product of putting a bullet in the right place. That part of decreased velocity from a short barrel is worth investigating.
How A Short Barrel Changes Velocity
If a short barrel decreases velocity so much that you shoot under your target, you’ve got a problem. This is the real reason for magnums and long barrels and hyper velocity and low drag/high B.C. bullets. All those things help a bullet go farther before falling, which makes it easier to hit what you want at unknown distances.
As a general rule, an inch less barrel will cost a bullet between 25 and 50 fps velocity. This varies depending on powder volume and the burning rate of that powder. The more powder and the slower its burning rate, the more barrel volume needed to burn it. Regardless, 50 fps of lost speed isn't much, so lets go radical and compare velocity from a 24-inch barrel and an 18-inch barrel and see how that changes downrange drop. The cartridge firing this bullet doesn’t matter, but bullet B.C. does, so we’ll standardize it at .450 and assign muzzle velocity at 3,000 fps for the 24-inch barrel. We’ll subtract 50 fps for each inch lopped off. We’re cutting back six inches. That equals 300 fps. Now lets run some numbers and see the downrange effect.
The columns most pertinent are Impact, which is where the bullets strike given our 250-yard zero range; Energy; and Drift, which reflects how far the bullet will be deflected by a right angle wind. Note that at 300 yards -- a long shot for most of us -- the bullet from the 18-inch barrel drops only an inch more than that from the 24-inch barrel. Drift is only an inch more, too. One lousy inch.
You can argue that the 16 inches of additional drop from the 18-inch barrel at 600 yards is a huge thing. That dimension is the chest measurement, brisket to backline, of a pronghorn and many whitetails. But... aside from the fact that few of us are properly equipped or trained to take such long shots, there is this device called a laser range finder that renders this insignificant.
Laser Nullifies Short Barrel Velocity Loss
The distance measuring precision of laser range finders is what makes long range shooting possible. Without that precise measurement, no one could accurately guess 600 yards vs. 700 vs. 500, and at those distances a 30-yard mistake can mean 7 to 10 inches of additional drop. Long range shooters live and die by their rangefinders. That makes drop virtually irrelevant.
Wait a minute. How can the drop from a short barrel be irrelevant? Well, because laser distance measurements are always combined with known trajectory curves, the second essential tool in effective long range shooting. Every serious, effective distance shooter knows the drops and drifts of his bullet. That ballistic information enables him/her to dial or select the correct reticle for each shot. Do you see where this is going?
As long as a shooter has a laser and trajectory chart, it doesn't matter if he's shooting 2,700 fps from an 18-inch short barrel or 3,000 fps from a 24-inch long barrel -- or 3,200 fps from a 28-inch super long barrel. The combination of precise range measurement and applied trajectory curve data equals precision shot placement (given proper gun handling, wind doping and trigger work.)
This information probably isn't going to induce many extreme range shooters to sell their 28-inch barreled 26 Noslers, but it should reassure regular and medium range hunters who are interested in the handling convenience of short barrel rifles. If most of your hunting/shooting is confined to 300 yards or less, you might want to consider saving some weight and making your field rifle easier to maneuver through thick cover by shortening its barrel. I wouldn't do this with a special, long range magnum, but anything in the 30-06 class and especially the short-action 308 class is a perfect candidate for a short barrel.
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