How Does Ammo Work? | Everything You Need To Know About Bullets

Main ideas and lessons

• Ammo is more than just a bullet. A “round” (cartridge) includes multiple interacting components that determine how it fires and performs.
• Ammunition basics reduce confusion. People get tripped up by:
  • numbers/letters/decimals in cartridge names
  • pressure-related suffixes (e.g., +P)
  • bullet/compatibility assumptions
• Cartridge “caliber” only tells part of the story. Diameter matters, but cartridge length, chamber specs, and pressure ratings determine whether ammo is safe/compatible.
• Bullet type strongly affects terminal performance. Different designs are optimized for:
  • range practice
  • self-defense / law enforcement
  • hunting
  • safety in training
  • long-range accuracy
  • specialized tactical roles
• Grain weight influences performance. Heavier vs. lighter bullets trade off velocity, recoil, stability, penetration, and wind sensitivity.
• Bullet shape and aerodynamics affect accuracy. Concepts like spitzer vs. flat nose vs. boat tail, and the ballistic coefficient (BC) help explain long-range behavior (drag, wind drift, velocity retention).
• Safety/selection rule: Match ammo to the markings on your firearm (barrel/frame). Don’t rely on appearance or only bullet diameter.

Methodology / practical guidance

• Step 1: Identify what a cartridge is made of

  • A standard modern round has four main components:
    • Case (outer shell)
    • Primer
    • Powder (gunpowder; typically smokeless)
    • Projectile / bullet (the part that exits the barrel)

• Step 2: Determine the correct “caliber” and compatibility

  • Treat caliber as bullet diameter only (not full compatibility).
  • Check firearm markings for the exact cartridge specification.
  • Do not assume interchangeability even when diameters or names sound similar.
  • Examples of “similar but not interchangeable” situations mentioned:
    • .223 Remington vs. 5.56 NATO
      • Similar bullet diameter, but different chamber specs/pressures.
      • Safe to shoot .223 in 5.56 (generally), but not the reverse (can be dangerous depending on rifle/ammo).
    • .308 Winchester vs. 7.62×51 NATO
      • Similar, but .308 may be loaded to slightly higher pressure / tighter tolerances.
    • .357 Magnum vs. .38 Special
      • Both use roughly .357” bullets.
      • .357 Magnum can shoot .38 Special, but not always/typically safely the other way (Magnum has longer case and higher pressure).

• Step 3: Choose bullet type based on intended use

  • Select from common bullet types:
    • FMJ (Full Metal Jacket)
    • JHP (Jacketed Hollow Point)
    • Soft point
    • Frangible
    • Ballistic tip
    • Specialty rounds (e.g., +P, subsonic, tracer, armor-piercing)

• Step 4: Consider grain weight for performance

  • Grain weight typically refers to bullet/projectile mass, not the full cartridge.
  • Heavier bullets:
    • usually more energy, better penetration, better momentum
    • often better stability and less wind drift at long range
    • typically lower velocity and more recoil
  • Lighter bullets:
    • usually higher velocity
    • can have less stopping/penetration and more wind drift effects

• Step 5: Consider bullet shape for aerodynamics

  • Bullet profiles discussed:
    • Spitzer/pointed: sharp pointed tip, low drag, precision/long range
    • Flat-nose: blunt nose, quick energy transfer for shorter ranges
    • Boat-tail: tapered rear, improved stability and velocity retention
    • Hollow point: expands on impact (can reduce aerodynamics due to cavity)

• Step 6: Use ballistic coefficient (BC) for long-range behavior

  • BC measures resistance to air drag.
  • Higher BC → less wind drift and less velocity loss, flatter/more predictable trajectory.

• Step 7: Store and use ammo safely

  • Emphasis on safe storage and choosing ammo matched to purpose (practice/defense/hunting).

Explanation of key components (ammo “what it’s made of”)

• Case

  • Holds everything together; commonly brass (also steel/aluminum).
  • Expands on firing to create a tight chamber seal, helping keep gas pressure going forward.

• Primer

  • At cartridge base; a sensitive metal cup with a shock-sensitive chemical.
  • Firing pin strike → spark → ignites powder (compared to a car’s spark plug).
  • Rimfire vs centerfire
    • Rimfire: primer in the rim
    • Centerfire: primer in the center

• Powder

  • Often smokeless powder (modern rounds); burns rapidly to generate chamber pressure.
  • Converts chemical energy into gas pressure that accelerates the bullet.

• Projectile (bullet)

  • Leaves the barrel, travels to the target, and its design determines impact behavior.

Bullet types and what they’re used for

• Full Metal Jacket (FMJ)

  • Soft lead core encased in hard metal jacket (often copper).
  • Pros: durable, reliable, affordable; less barrel lead fouling.
  • Cons: tends to not expand, so greater risk of over-penetration in self-defense contexts.

• Jacketed Hollow Point (JHP)

  • Jacket with hollow point tip that expands on impact.
  • Goal: transfer more energy, reduce over-penetration risk, improve stopping potential.
  • Common for: self-defense / law enforcement.

• Soft Point

  • Partially exposed lead tip.
  • Expands but more controlled than hollow points; penetrates deeper.
  • Common for: hunting (especially medium/large game).

• Frangible

  • Designed to break apart on impact with hard surfaces (steel/concrete).
  • Pros: reduces risk of ricochet/backsplash; often for indoor/close training.
  • Cons: not for deep penetration; not suitable for self-defense/hunting larger animals.

• Ballistic Tip

  • Plastic tip drives back into bullet on impact to initiate expansion.
  • Pros: improved aerodynamics (better long-range flight), while still providing expansion.
  • Common for: long-range hunting and varmint hunting.

Specialty ammunition concepts mentioned

• +P ammunition

  • Loaded to higher pressure than standard.
  • Produces more velocity/energy; can increase stopping power.
  • Caution: not all firearms are rated for +P—check specs.

• Subsonic

  • Designed to travel below the speed of sound (~1,000 ft/s as stated).
  • Used with suppressors to reduce noise; avoids the supersonic “crack.”
  • Includes an anecdote about a suppressed “Q Honey Badger.”

• Tracer rounds

  • Contains incendiary material that lights up as it travels, leaving a visible trail.
  • Used for target identification/adjusting fire in low light.
  • Mostly military/tactical; not typically practical for civilian use.

• Armor-piercing

  • Designed to penetrate hard armor (vests/vehicles).
  • Uses harder materials (examples: tungsten/steel).
  • Restricted/illegal in many jurisdictions for civilian use.

Grain weight (mass) and how it affects behavior

• Definition and conversion
  • 1 grain = 1/7000 of a pound (video also provides approximate grams).
• Performance effects
  • Heavier bullets: more energy/momentum, better penetration, improved stability, less wind drift; but lower velocity and more recoil.
  • Lighter bullets: higher velocity; but less penetration/stopping power and more wind/trajectory sensitivity.

Bullet shape and ballistic coefficient (BC)

• Bullet shapes

  • Spitzer: reduced drag; long-range precision
  • Flat-nose: energy transfer quickly at shorter ranges
  • Boat-tail: tapered rear improves stability/velocity retention
  • Hollow point: expansion on impact; cavity may reduce aerodynamic efficiency

• Ballistic coefficient (BC)

  • Higher BC = less drag, less wind drift, less velocity loss.
  • Mentioned as a reason long-range shooters/snipers prefer high-BC ammo.

Sponsor mention (source featured)

• Ammo Squared is promoted as a sponsor (“America’s ammunition reserve”)
  • Claims: choice of 70+ calibers, monthly budget building, climate-controlled storage, free shipping over $250, no hidden fees/minimums.

Speakers / sources featured

• Primary speaker: the video host/narrator (name not stated in subtitles).
• Sponsor/source mentioned: Ammo Squared.
• Referenced person: “Tanner” (mentioned in jokes/aside; not otherwise identified).