Wednesday, January 5, 2011

Sniper Rifles


Sniper Rifles

The first thing to know about sniper rifles is that they don’t do any more damage than any other rifle of the same caliber.  The US M24 sniper rifle fires the same 7.62 NATO round as the M-60 machinegun, and M-14 battle rifle.  Sort of.  There are small changes with the shape of the bullet, but there is no significant difference in the velocity or energy.

So, why are Sniper Rifles so special?


Consistency.  When speaking of rifles and accuracy, there is a term that comes up often: Minute of Angle, or MOA.  A circle is divided into 360 degrees.  Each degree is divided into 60 arcminutes.

This is math.  Ride it out, it’s important.

When measuring separation of two points that may or may not be different distances, feet and inches don’t work.  Neither do meters, so settle down, metric.  This is commonly used in astronomy.  Two stars may be separated by hundreds or even thousands of light years in real space, but when we describe their separation as seen from Earth, we might say they are four degrees apart.  This same method is used when talking about rifle accuracy.  One MOA doesn’t need to know how far away the target is.  It only looks at the space between the holes in the paper.

When we say a rifle has one minute of angle accuracy, it means that no bullet will hit outside of a circle that spans 1/60th of a degree.  In one of the few cases where two non-metric units of measure play well together, 1 MOA is equal to 1 inch at 100 yards.  That works out to 2.54 cm at 91.4 m.

Minute of angle accuracy is fine for a hunting rifle, but think of it like this.  At 500 yards, that circle will be 5 inches across.  That’s not really a lot smaller than a human head.  At 1500 yards, that circle is now 15 inches.  Snipers need to be much more precise than that, especially since they deal in ranges over a mile (1760 yards/1.6 km).  In bench rest rifle competitions, the best shooters are getting group sizes around 0.1 MOA out to 200 yards.  That would be a 0.5 inch group at 500 yards assuming that wind and other outside conditions were not a factor.

In reality, it doesn’t scale up like that, but they are still much better than a regular hunting rifle, and that’s the key.  Sniper rifles don’t do more damage, they simply do their damage in exactly the right spot.

Obviously, the rifle itself is a significant part of it, but just as important is the telescopic sight, or Scope.  A rifle scope is basically the same thing as a spyglass, or one side of a pair of binoculars.  It magnifies an image to make it appear closer.  This allows for a shooter to make tiny corrections to the point of aim.

A six power scope, written 6x, is one that increases the magnification six times.  A target at 600 yards would look like that same target is only 100 yards away, and that’s the first place movies and TV shows screw things up.

When movies let us see “through the scope” we can clearly see the target’s eye color.  We can see tiny details from 1000 yards away that would be hard to spot from across a coffee table.  Most sniper scopes are under ten power.  Bench rest rifles sometimes have scopes that go as high as thirty power.  At 1000 yards, a 30x scope will make the target look like they are 100 feet away.  That’s about the distance from one end of a basketball court or hockey rink to the other, and about 1.5 times further than the pitcher’s mound from the home plate in baseball.  Plenty close enough to recognize someone, but still not enough to read the serial number off the money being exchanged at the drug buy.  Also check out the accessories entry when I get it done.

Another critical aspect to the use of a sniper rifle is the shooter.  Just having the rifle and knowing the range is of no use without a better than average ability to read the wind, breathe properly, and account for variations in elevation and terrain.  Not just anyone will be able to pick up a sniper rifle and make impossible shots.

The last thing I want to say about sniper rifles is about the rifle itself.  A common question I see on forums is, “What type of gun could make a good sniper rifle?”  A good rule of thumb answer is anything you could use to hunt deer or elk.  The US Army Sniper Rifle is basically just a Remington 700 bolt action rifle with some extra work done on it.  The Marine Sniper Rifle is based on the M-14.  Both are available on the civilian market in the US in most places.  There are certain changes made to them, but most of those can be done in about a day in a basement.

That said, there are several rifles that are built with the sole idea of sniping in mind.  These are often in non-standard calibers and may be hard to find in the civilian world, depending on the setting.

The last thing I want to mention is another myth that has been reinforced by film and TV for decades.  The image of a sniper with a bipod or balled up coat serving as a rest on a window sill is so common that it’s accepted even in shows that try hard to get things right.  In the real world, the sniper will stay away from the window as much as possible.  They might climb up onto something in the back of the room, or set up in the rafters several yards from the opening they plan to use.  From outside the building, no one should be able to look up and see the barrel of the rifle unless the person doing the shooting doesn’t really know what they are doing, or the target will be moving too quickly to take the shot any other way.

1 comment:

  1. You know your projects stand out of the herd. There is something special about them. It seems to me all of them are really brilliant! utg scopes

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