With long range shooting gaining tons of interest in recent years, I often get people asking me how far they can shoot with their .308 Winchester rifle. While there certainly are more capable calibers than a .308 Winchester for long range shooting, this doesn’t take away from the fact that the .308 is one of the most popular rifle cartridges used worldwide. So how far can the cartridge accurately and consistently engage targets?
There are many factors that go into determining a rifles effective range. The simple answer is that with a good bullet, a .308 can shoot effectively up to around 1000 meters at sea level pressure. While aerodynamical ability in projectiles has advanced tremendously in recent years, this range can be extended even further by selecting the right bullet for longer distances.
Effective range is the distance a well-aimed bullet can hit a target accurately. A bullet shot can actually travel far past its effective range, but it is not certain if it will hit its target then, even if the shot was well-aimed.Wikipedia
This isn’t to say that a .308 can’t make accurate shots at further distances. There are many ways that a rifle owner can increase the effective range of his rifle, which we will discuss below. But before doing so, it is important to note that inadequate equipment (rifle, scope and ammunition) or shooting ability will cause the shooter to struggle in reaching distances far shorter than a rifle’s effective range. A standard .308 hunting setup for example will typically engage distances up to about 350 meters, and not much further.
How Can I Determine my Rifle’s Effective Range?
Your rifle’s current effective range can be determined by entering the muzzle velocity, your projectile’s ballistic coefficient, and your average atmospheric pressure into a ballistics calculator, and then determining at which point your projectile transitions from supersonic to subsonic speed – known as the bullet’s transonic range.
Tip: ballistic coefficient (BC), which is a figure representing your bullet’s ability to overcome air resistance in flight, can be found on the ammunition box or the manufacturer’s website.
The velocity at which your projectile will breach the sound barrier sits at around 343mps or 1,125fps (in dry air, at 20°C). From this point onward, the projectile’s trajectory most often becomes indeterminable and accuracy is lost.
Above: the effective range of this .308 Winchester 168gr SMK bullet (muzzle velocity of 2500fps) is 800 meters, at standard sea-level pressure. We can see how the velocity of the projectile is about to breach the sound barrier speed. Once the bullet crosses the sound barrier, it either tumbles or moves onto a new trajectory caused by disturbance. This bullet has a ballistic coefficient of 0.424
How Can I Increase my Rifle’s Effective Range?
Increasing a rifle’s effective range can be achieved in one or more of the following ways:
- Increasing muzzle velocity
- Selecting a bullet with a higher ballistic coefficient (more aerodynamical)
- Moving your firing point to a higher altitude (lower air pressure)
Increasing Muzzle Velocity
The muzzle velocity of a rifle can be increased in two ways:
- by safely upping the propellant charge within the cartridge during handloading.
- or by purchasing a longer barrel.
Increasing Propellant Charge
An increase in propellant will produce more gasses that propel the projectile through the rifle’s bore, increasing pressure and producing a higher velocity.
Example: if a cartridge for the above 168gr SMK load is increased by 2.5grains of powder, we can expect an approximate increase of 180fps in muzzle velocity, which would extend effect range by around 80 to 90 meters.
It is important to watch for signs of overpressure when increasing the amount of propellant in a cartridge, and you should known that it will increase felt recoil (although only slightly), and may significantly reduce the barrel’s accurate lifespan.
Selecting a Longer Barrel
Having a longer barrel increases muzzle velocity, as the bullet has more time to accelerate within the barrel while being driven by the propellant’s burning gases, which in turn, increases the effective range of the rifle, allowing the bullet to travel further.
While .308 rifles intended for tactical use or hunting typically accommodate barrels up to around 24-inches, some rifle’s which are built for benchrest shooting are fitted with barrels up to 30-inches in length. These are cumbersome and hinder the shooter’s ability to effectively carry the rifle on foot through various terrain, but may add an extra 100 meters onto the rifle’s effective range capability.
Selecting a more Aerodynamical Bullet
When long range is your goal, you will require better quality ammunition than what is considered to be normal. This is typically known as match grade ammunition, or match grade bullets, and can be defined as ammunition that is suitable for a competitive match.
Match grade ammunition is designed to be more consistent and accurate than cheaper general-use ammo, and comes with a higher ballistic coefficient, meaning that the bullet is more aerodynamical and of a higher quality.
The Open Tip Match bullet is often a common choice for long range target shooting, while the Ballistic or Plastic Tipped bullet is often the preferred choice for long range target shooting that is also suitable for hunting. A Very Low Drag (VLD) bullet has the most efficient flight path, but may be too long to seat in some rifle magazines.
The chart below provides an example using the listed bullets, producing an effective range for each at sea-level pressure:
- Delsing Soft Point Hunting bullet, 168grain
- Sierra Match King Open Tip Match bullet, 168grain
- Hornady ELD Match VLD bullet, 168grain
|168gr Soft Point
|168gr Match King
|168gr ELD Match
We can see by the above chart that although the muzzle velocities and the bullet weights are identical, there is a vast difference in range capability, with the VLD bullet effectively outranging the hunting bullet by almost 450 meters.
Shooting at Higher Altitude
The final way that you can improve your .308 Winchester’s effective range, is by shooting at a higher altitude or in lower air pressure.
Pressures closer to sea level (averaging 1,013 millibars) creates a much thicker air when compared to pressures at higher altitudes. This thicker air puts more drag onto your bullet as it flies through the air, slowing it down at a faster rate. Shooter’s who live at higher altitudes will most often find themselves capable of out-ranging shooters who live closer to sea-level.
|168gr SMK at 2500fps
|168gr SMK at 2500fps
|1500m above Sea-level
|168gr SMK at 2500fps
|3000m above Sea-level
The above chart uses average pressures at altitude. 1,013millibars at sea-level; 853millibars at 1500m; and 722millibars at 3000m.
The results depicted by the chart above can be surprising to many shooters who were previously unaware of the effects on a projectile caused by altitude. Shooters in higher altitudes therefore gain an advantage in effective range thanks to the thinner air.
You should now have a good understanding on how far you can shoot your rifle before your trajectory becomes unpredictable, while also having a good understanding on ways to improve your range capability if desired. So fiddle around with a ballistics app, and then head out to the range and test your predicted results.
If you’d like to know more about our top 10 rifle bullets that excel at long range, read the following article: The Best Bullets for Long Range Precision.