Ballistics is one of those topics that sounds complicated until you break it down. Once you understand the basics, you’ll make smarter ammo choices, shoot more accurately, and spend less money on rounds that don’t perform the way you expect. Here’s everything you need to know without the textbook fluff.
What “Ballistics” Actually Means
There are three phases every bullet goes through:
- Internal ballistics – what happens inside the gun (pressure, burn rate, barrel twist).
- External ballistics – the bullet’s flight from muzzle to target (trajectory, wind drift, velocity loss).
- Terminal ballistics – what happens on impact (expansion, penetration, energy transfer).
Most shooters obsess over external and terminal performance because that’s what shows up on paper and on game. Let’s dig in.
Key External Ballistics Factors You Can’t Ignore
Bullet Drop and Trajectory
A .223 Remington 55-grain FMJ drops about 36 inches at 500 yards. Swap to a 77-grain match load with a higher ballistic coefficient and that same distance only drops ~28 inches. That 8-inch difference is the reason long-range shooters chase high-BC bullets.
Pro tip: Zero your rifle at 100 yards, then use a ballistics calculator (Strelok, Hornady 4DOF, etc.) with the exact ballistic coefficient and muzzle velocity printed on the box. True Shot lists verified chrono data on most SKUs so you’re not guessing.
Ballistic Coefficient (BC): The Single Most Misunderstood Number
Higher BC = less drag = flatter trajectory + better wind resistance. Example:
- .308 Win 168 gr Federal Gold Medal Match – G1 BC ≈ .450
- .308 Win 175 gr same line – G1 BC ≈ .505
That .055 difference keeps the heavier bullet supersonic 150-200 yards farther and drifts roughly 20% less in a 10 mph crosswind. Real-world advantage, not marketing hype.
Wind Drift: The Great Equalizer
At 400 yards in a full-value 10 mph wind:
- 9mm 124 gr +P (BC ~.155) drifts almost 30 inches
- 6.5 Creedmoor 140 gr ELD-M (BC ~.646) drifts under 8 inches
Wind reads are never perfect, so low-drift cartridges forgive more mistakes.
Terminal Ballistics: What Happens When the Bullet Hits
Two schools of thought dominate:
- Energy dump / hydrostatic shock – favored by many AR pistol and 5.56 defenders.
- Penetration + permanent wound channel – FBI standard (12-18" in ballistic gelatin) and the reason most duty ammo is now bonded or solid copper.
Modern bonded hunting bullets (Nosler Partition, Federal Terminal Ascent, Hornady ELD-X) and duty loads (Speer Gold Dot, Federal HST) split the difference: reliable expansion to 1.5–2× caliber while still punching deep enough.
Sectional Density Matters More Than You Think
Sectional density (SD) = bullet weight (grains) ÷ 7000 ÷ diameter² Higher SD = better penetration. Example:
- .308 150 gr soft point – SD ≈ .226 (deer round)
- .308 180 gr – SD ≈ .271 (elk/moose territory)
Same velocity, the heavier bullet drives deeper because it’s longer for its diameter.
Muzzle Velocity vs. Real-World Velocity
Box velocity is almost always measured with a 24" test barrel. Your 16" AR or 20" bolt gun will be 50-150 fps slower. That velocity loss hurts light-for-caliber varmint bullets far more than heavy match or hunting pills. Always check barrel-length velocity data when it’s available—True Shot includes it on popular SKUs.
Reading the Box Like a Pro
Next time you’re staring at ammo on the shelf, look for these numbers:
- Bullet weight (grains)
- Bullet type (FMJ, HP, Polymer tip, etc.)
- Ballistic coefficient (G1 or G7)
- Advertised velocity (and what barrel length it came from)
Everything else is noise.
Quick Reference Cheat Sheet
| Caliber | Typical BC Range | Best Use Case | Realistic 500-yd Drop (200-yd zero) |
|---|---|---|---|
| 5.56 55 gr | .240–.270 | Training / plinking | ~45–50" |
| 5.56/223 77 gr | .360–.420 | Precision / coyotes | ~28–32" |
| .308 168–175 gr | .450–.530 | All-purpose / deer | ~34–38" |
| 6.5 Creedmoor 140–147 gr | .600+ | Long range / big game | ~24–28" |
| .300 Win Mag 200+ gr | .600–.700+ | Elk / 1000-yard steel | ~20–25" |
Final Thought
Ballistics isn’t magic—it’s physics you can predict and control. Match the bullet’s ballistic coefficient, sectional density, and construction to your barrel length and intended game or target distance and you’ll shoot tighter groups and drop game cleaner.
Ready to put this knowledge to work? Head over to True Shot Ammo—we stock everything from budget FMJ to the latest match-grade and monolithic hunting loads. See you at the range.
