You’ll want to remember a few things when choosing your gun firing ammunition.
You must, for instance, consider the bullet weight, caliber, load type, bullet type, etc. Why is this crucial? …because all these factors determine your bullet’s performance.
Further, you’ll want to remember to check the muzzle velocity.
In fact, muzzle velocity is one of the most critical considerations when scouting for ammo, whether you’re a seasoned hunter, beginner, or experienced marksman.
Self-defense, competition, and target rounds perform particular muzzle velocities.
From modern rifles to conventional guns, velocity is an essential performance metric to understand whether you’re going for a hunt or shooting practice.
Look around; velocity numbers are everywhere, from ballistics statistics to bullet packaging and on the bullets.
That said, you’ll learn the following by the tail end of this article:
- What muzzle velocity is
- Factors affecting muzzle velocity
- How muzzle velocity affects your shooting
Let’s get cracking;
What is Muzzle Velocity?
Muzzle velocity is a term used to describe the projectile speed once it leaves your gun barrel.
The velocity is measured in feet per second (fps). Muzzle velocity is at its highest soon after the projectile leaves the barrel.
You can measure muzzle velocity for all gun firing ammunition, enabling you to compare similar ammo types.
You can measure muzzle velocity in a full-metal jacket, birdshot, and shotgun ammunition. Still, it is essential to remember that projectile velocity isn’t an excellent way to compare ammo for varying purposes since downrange performance will be different.
Factors Affecting Muzzle Velocity
The three main factors that determine the muzzle velocity of any gun. These are:
- Propellant quality and quantity
- Barrel length
- Bullet weight
Let’s expound on this further:
Every ammunition round has four components; the bullet, propellant power, case, and primer.
When you fire your gun, the primer ignites the propellant, which then burns in a controlled explosion before forcing the bullet down the length of the barrel.
Simply, the higher the quality of the propellant in your cartridge, the higher/faster the explosive energy, resulting in more muzzle velocity.
According to physics, the heavier the object, the more force you need to move the time. Similarly, weight affects the velocity of the bullet; heavier bullets have slower velocities than their lighter counterparts with all the variables constant.
Projectile mass is measured in grains (gr).
The lightest bullets weigh 15gr for 17HM rifle cartridges, while heavier bullets can weigh as much as 750gr for 0.50 BMG rifles.
The more acquainted you are with guns firing ammunition, the easier it is to determine what is heavy or light regarding bullet weight.
Side Note: While muzzle velocities for heavier bullets are slower, they’re less inclined to elements like air drag over long distances. Such a bullet tends to hit the target more accurately than a light bullet.
A longer barrel implies more muzzle velocity. A bullet fired from rifles and shotguns with a longer barrel has an extended travel time for the burning gunpowder, thus a higher muzzle velocity.
On the other hand, a handgun with a short barrel has less chamber diameter and, by extension, a slower burning propellant for the pressurized gas to act on the projectile from the explosion.
Why is Muzzle Velocity Important?
Muzzle velocity affects your shooting in several ways, including;
It Reduces the Time of Flight
Suppose you fire two similar bullets from the same caliber and the equal ballistic coefficient. In that case, the bullet that leaves the barrels with more energy at a higher muzzle velocity will hit the intended target sooner.
Why does this matter?
Because the faster the bullet's velocity, the more it can resist drag, air, and gravity. Further, projectiles traveling at high speed over long distances minimize an animal's chances of escaping between the time you pull the trigger and when the bullet lands.
It Flattens Trajectory
Apart from enabling a bullet to overcome earth’s gravity, muzzle velocity also reduces bullet trajectory.
When the .30-30 Winchester graced the market, it was touted to be a long-range cartridge, with bullet hits zeroed to strike targets about 2.5 inches at 100 years, you could hold dead-on and take out targets at 175 yards.
Meanwhile, you could hold dead-on out at about 260 yards with the .30/06 load, which boasted a muzzle velocity of 700 fps, 35% faster than the Winchester.
Modern rifles with .30.06 loads have more velocity allowing you to dead-on hold at 300 yards.
It Makes Your Bullets Hit Harder
While there are several ways to calculate muzzle velocity, determining the kinetic energy is the most popular.
For starters, you can calculate kinetic energy by squaring the impact velocity.
That said, you can calculate how hard your bullet will hit a target as follows:
Kinetic energy = (Impact Velocity Squared X Bullet Weight)
Staying with the original 0.30/06 load and a 150gr bullet at a relatively high velocity of $2,700 fps, the kinetic energy at the barrel is 2,427 foot-pounds.
If you bump up the muzzle velocity by 100 fps, you’ll raise the kinetic energy by 184-foot pounds.
It Drives Expansion
Impact velocity determines bullet deformation and expansion.
Rifle bullets built to deform upon impact must hit the target at a particular velocity for that to happen. The latest big game bullets require a muzzle velocity range of 1,400 to 2,000 fps, depending on the design.
If your bullet’s impact velocity doesn’t have the required deformation capacity, it won’t expand. It’ll create a small hollow point equal to the bullet’s diameter.
So, if you’re a long-range hunter, you’ll benefit from higher velocity.
It Controls Penetration
A couple of factors affect how far a bullet can penetrate. These include:
- What comes into contact with the bullet as it penetrates
- How large or wide the bullet’s frontal diameter gets during penetration
Still, a bullet will struggle to penetrate deeper without enough muzzle velocity.
It Helps with Accuracy
Even though muzzle velocity doesn’t significantly affect accuracy at close range, it has a notable impact over 500 yards.
Still, more velocity doesn’t increase accuracy but rather the velocity’s consistency.
If you sight a .30/06 load at 100 yards, for instance, the projectile will drop at around 687 inches at 500 yards. A velocity variation of 76 fps would result in the bullet dropping five more inches.
The Bottom Line
Muzzle velocity matters at every distance, and it's crucial to know your ammunition's velocity. Understanding the rated velocity at various distances can be a game changer if you're a marksman or a long-range hunter.
While your bullet's design and energy downgrade are crucial; nothing is possible without muzzle velocity.