Complete Guide to Handgun Ammunition & Caliber Selection: From Basics to Competition Shooting

Complete Guide to Handgun Ammunition & Caliber Selection

Why Does Ammunition Selection Matter So Much?

In the shooting sports world, most people focus on the firearm itself — the brand, model, and how it feels in hand — while often overlooking an equally important factor: ammunition. In reality, your ammunition choice directly affects shooting accuracy, felt recoil, training costs, and even determines whether you can legally compete in a match.

Imagine this: you spend top dollar on a CZ Shadow 2, carefully select a competition holster and belt, only to be disqualified on match day because your ammunition doesn’t meet Power Factor requirements — this situation is more common in actual competitions than you might think.

Whether you’re a beginner just getting into shooting, an intermediate shooter planning your training, or a competitive shooter preparing for IPSC/IDPA matches, understanding ammunition basics and selection principles is essential.

This Guide Covers

  • Basic ammunition structure and components
  • Complete comparison of popular handgun calibers
  • Bullet types and their applications
  • IPSC/USPSA and IDPA Power Factor rules
  • Practice ammo vs. match ammo selection strategies
  • Introduction to handloading (reloading)
  • Ammunition storage and safety guidelines

Read more: After choosing your ammunition, you’ll need a solid training plan. Check out our Personal Shooting Training Plan Guide to learn systematic training methods.

Basic Ammunition Structure

Before selecting ammunition, understanding what a cartridge is made of provides the foundation for understanding all the different specifications.

Four Core Components

A complete handgun cartridge consists of four core components:

1. Bullet (Projectile)

The bullet is the part that actually exits the barrel when fired. Its weight is measured in “grains” (gr), where 1 grain equals approximately 0.065 grams. Bullet weight directly affects recoil, trajectory, and terminal performance. For 9mm, common bullet weights include 115gr, 124gr, and 147gr.

2. Casing (Case)

The casing is the outer shell that holds all components together. Common materials include brass, steel, and aluminum. Brass casings are most prevalent because they seal the chamber effectively during firing, prevent high-pressure gas leakage, and can be collected for reloading.

3. Powder (Propellant)

Powder is the propellant in the cartridge. When ignited, the powder rapidly combusts to generate high-pressure gases that push the bullet through the barrel. Different powder formulations burn at different rates, affecting chamber pressure, muzzle velocity, and recoil characteristics.

4. Primer

The primer sits at the base of the casing. When struck by the firing pin, the primer’s sensitive compound detonates and ignites the powder. Handgun ammunition primers come in two sizes:

  • Small Pistol Primer: Used in 9mm, .40 S&W, .380 ACP, etc.
  • Large Pistol Primer: Used in .45 ACP, 10mm, etc.

Reading Ammunition Labels

When purchasing ammunition, you’ll see labels like these:

Label Example Meaning
9mm Luger 124gr FMJ 9mm caliber, 124 grain bullet, Full Metal Jacket
.45 ACP 230gr JHP .45 caliber, 230 grain bullet, Jacketed Hollow Point
.40 S&W 180gr TMJ .40 caliber, 180 grain bullet, Total Metal Jacket
9mm +P 124gr 9mm overpressure, 124 grain bullet

The +P designation means “Plus Pressure,” indicating higher chamber pressure than standard spec, resulting in faster velocity and more energy but also noticeably more recoil. Make sure your handgun is rated for +P ammunition before using it.

Caliber selection is an enduring topic in the shooting world. Here’s a comprehensive comparison of mainstream calibers covering competition, defense, and training perspectives.

9mm Luger (9x19mm Parabellum)

9mm is the most popular handgun caliber in the world today, dominating across law enforcement, military, and competitive shooting.

Specification Data
Common Bullet Weights 115gr / 124gr / 147gr
Typical Muzzle Velocity 1,100-1,400 fps
Typical Muzzle Energy 320-400 ft-lbs
Felt Recoil Low to moderate
Magazine Capacity 15-21 rounds (full-size pistols)
Cost Per Round ~$0.25-0.40

Advantages:

  • Mild recoil enables faster follow-up shots and sight recovery
  • Highest magazine capacity means fewer reloads
  • Lowest ammunition cost, ideal for high-volume practice
  • Nearly every major handgun platform offers a 9mm variant
  • Modern bullet engineering has significantly improved defensive performance

Best For: IPSC/USPSA Production, IDPA SSP/CCP/CO, general training, defensive use

.40 S&W

The .40 S&W was championed by the FBI in the 1990s as a compromise between 9mm and .45 ACP.

Specification Data
Common Bullet Weights 165gr / 180gr
Typical Muzzle Velocity 950-1,200 fps
Typical Muzzle Energy 400-500 ft-lbs
Felt Recoil Moderate to high (snappy)
Magazine Capacity 13-17 rounds
Cost Per Round ~$0.35-0.50

Advantages:

  • Can achieve Major Power Factor in USPSA Limited/Limited 10
  • Higher energy than 9mm
  • Uses similar-sized frames as 9mm pistols

Disadvantages:

  • Felt recoil is sharper than .45 ACP due to higher chamber pressure
  • Higher ammunition cost than 9mm
  • Lower magazine capacity than 9mm
  • Many agencies have transitioned back to 9mm in recent years

Best For: USPSA Limited division (Major Power Factor), shooters who prefer larger calibers

.45 ACP

The .45 ACP served the U.S. military from World War I through Vietnam and has over a century of history.

Specification Data
Common Bullet Weights 185gr / 200gr / 230gr
Typical Muzzle Velocity 830-1,050 fps
Typical Muzzle Energy 350-450 ft-lbs
Felt Recoil Moderate (slow push, softer feel)
Magazine Capacity 7-14 rounds
Cost Per Round ~$0.40-0.60

Advantages:

  • Recoil has a slow “push” characteristic; many shooters find it more comfortable than .40
  • Large bore diameter for terminal effectiveness
  • Standard caliber for classic 1911 pistols
  • Most .45 ACP loads are subsonic (under 900 fps), resulting in relatively lower noise

Disadvantages:

  • Lowest magazine capacity
  • Highest ammunition cost
  • Pistols are typically larger and heavier
  • Declining popularity in modern competitive shooting

Best For: 1911 enthusiasts, USPSA Single Stack, shooters who prefer the classic style

.380 ACP (9mm Short)

The .380 ACP is essentially a smaller version of 9mm, primarily used in compact concealed carry pistols.

Specification Data
Common Bullet Weights 90gr / 95gr
Typical Muzzle Velocity 900-1,000 fps
Typical Muzzle Energy 170-200 ft-lbs
Felt Recoil Low
Magazine Capacity 6-10 rounds

Best For: Concealed carry backup guns, recoil-sensitive shooters

.357 SIG

The .357 SIG replicates .357 Magnum ballistics in a semi-automatic platform.

Specification Data
Common Bullet Weights 125gr
Typical Muzzle Velocity 1,350-1,450 fps
Typical Muzzle Energy 500-550 ft-lbs
Felt Recoil High

Best For: Shooters seeking high velocity, certain law enforcement agencies

Caliber Selection Summary

Caliber Recoil Capacity Cost Competition Use Recommended For
9mm Low High Low Excellent Best choice for most shooters
.40 S&W Med-High Medium Medium Good USPSA Limited shooters
.45 ACP Medium Low High Fair 1911 enthusiasts
.380 ACP Low Low Medium Poor Concealed carry

Recommendation: If you’re a beginner or primarily shoot competition, 9mm is the best choice in the vast majority of situations. Lower recoil helps you master fundamentals faster, lower cost allows more practice volume, and higher capacity is an advantage in competition.

Bullet Types and Applications

Comparison of various bullet types

Different bullet designs serve different purposes. Choosing the wrong bullet type can affect training effectiveness or even violate match rules.

FMJ (Full Metal Jacket)

FMJ is the most common bullet type for practice and training. The bullet has a lead core enclosed in a copper alloy jacket.

  • Use: Range practice, training, competition
  • Characteristics: Does not deform or expand; higher penetration
  • Pros: Affordable, reliable feeding, reduced lead exposure
  • Cons: Not suitable for defensive use (over-penetration risk)

TMJ (Total Metal Jacket)

TMJ is similar to FMJ but the metal jacket completely encloses the bullet base, leaving no exposed lead.

  • Use: Indoor range practice (reduced lead vapor)
  • Characteristics: More environmentally friendly than FMJ
  • Pros: Minimized lead exposure for shooters
  • Representative Brands: Speer Lawman, Federal Syntech

JHP (Jacketed Hollow Point)

JHP bullets have a cavity in the tip that causes the bullet to expand upon impact, creating a larger wound channel.

  • Use: Self-defense, law enforcement
  • Characteristics: Expands on impact with soft targets, reducing over-penetration
  • Pros: Greater stopping power, safer for bystanders
  • Cons: Higher cost, potential feeding issues in some pistols

Common Competition Bullet Types

Bullet Type Competition Use Notes
FMJ 115-124gr IPSC Production Minor Most economical option
FMJ/TMJ 147gr IDPA, USPSA Minor Heavier bullet, subsonic, soft recoil
FMJ 180gr (.40) USPSA Limited Major Achieves Major Power Factor
Syntech 150gr USPSA/IDPA Low recoil, protects steel targets, officially certified

Match Tip: Federal Syntech Action Pistol 150gr is USPSA’s officially certified ammunition, designed specifically for competitive shooting. It uses a synthetic jacket instead of traditional copper, reducing damage to steel targets while delivering consistent Power Factor performance.

Power Factor Rules for Competition Shooting

Competition shooting match scene

If you plan to compete in IPSC, USPSA, or IDPA matches, Power Factor (PF) is a core concept you must understand. It directly affects your ammunition selection and match scoring.

What Is Power Factor?

Power Factor is a standardized measurement of ammunition energy, calculated as:

Power Factor = Bullet Weight (grains) x Muzzle Velocity (fps) / 1,000

Example: A 124gr 9mm bullet fired at 1,050 fps:

  • PF = 124 x 1,050 / 1,000 = 130.2

IPSC/USPSA Power Factor Requirements

Classification Power Factor Scoring Difference
Minor 125-164 A=5, C=3, D=1
Major 165+ A=5, C=4, D=2

Key Points:

  • The minimum threshold for legal ammunition is PF 125
  • A-zone scores are identical for Major and Minor (both score 5 points)
  • The difference appears in C-zone and D-zone: Major scores 4 in C (vs. Minor’s 3) and 2 in D (vs. Minor’s 1)
  • Ammunition velocity is verified at matches via chronograph — failure to meet the declared threshold results in reclassification or disqualification

Power Factor by Division

IPSC Divisions

Division Major PF Minor PF
Open 160 125
Standard 170 125
Classic 170 125
Production N/A 125
Production Optics N/A 125
Revolver 170 125

USPSA Divisions

Division Major PF Minor PF
Open 165 125
Limited 165 125
Limited 10 165 125
Production N/A 125
Carry Optics N/A 125
Single Stack 165 125
PCC N/A 125

Note: Production and Carry Optics divisions only accept Minor Power Factor. Even if your ammunition reaches Major standards, it will only be scored as Minor.

IDPA Power Factor Requirements

IDPA’s Power Factor rules differ from USPSA. IDPA does not differentiate between Major/Minor scoring, but each division has a minimum Power Factor threshold:

  • SSP (Stock Service Pistol): Minimum PF 125
  • ESP (Enhanced Service Pistol): Minimum PF 125
  • CCP (Compact Carry Pistol): Minimum PF 125
  • CO (Carry Optics): Minimum PF 125
  • REV (Revolver): Minimum PF 125

In IDPA competition, if your ammunition fails to meet the minimum Power Factor for your division, your score will be recorded as a disqualification (DQ).

How to Ensure Your Ammo Makes Power Factor

  1. Buy branded ammunition: Choose reputable practice ammo brands — they typically exceed PF 125 consistently
  2. Use a chronograph: Purchase or borrow a chronograph to test your ammunition velocity
  3. Build in a margin: Target a PF at least 5-10 points above the minimum (e.g., aim for PF 133-135)
  4. Temperature effects: Cold weather reduces powder burn efficiency, potentially dropping velocity by 30-50 fps

Read more: Learn more about IPSC match rules in our IPSC Match Procedure and Preparation Guide.

Practice Ammo vs. Match Ammo Selection Strategy

Smart shooters use different ammunition strategies for practice and competition, controlling costs while ensuring match performance.

Practice Ammunition Selection Principles

The primary considerations for practice are cost and reliability:

Recommended Practice Ammo (9mm):

Brand/Model Bullet Weight Type Features
Magtech Target 115gr FMJ Great value, stable supply
Federal American Eagle 115gr FMJ Consistent quality, made in USA
S&B (Sellier & Bellot) 115gr/124gr FMJ European made, excellent brass quality
Winchester White Box 115gr FMJ Affordable, widely available
Blazer Brass 115gr FMJ Budget-friendly

Practice Ammo Tips:

  • Prefer brass-cased ammunition — casings can be collected for future reloading
  • Avoid steel-cased ammunition in precision pistols — it may accelerate wear
  • For indoor ranges, use TMJ or Syntech to minimize lead exposure
  • Buying in bulk (1,000+ rounds) typically yields significant discounts

Match Ammunition Selection Principles

Match priorities are consistency and Power Factor compliance:

Recommended Match Ammo (9mm Minor):

Brand/Model Bullet Weight Features
Federal Syntech Action Pistol 150gr USPSA certified, low recoil
Atlanta Arms Competition 124gr Designed for competition, consistent PF
S&B 124gr FMJ 124gr Great value, consistent quality

Match Ammo Tips:

  • Practice with the same ammo you’ll use in competition to confirm feel and PF
  • Use the same lot number throughout an entire match
  • Chrono at least 10 rounds before a match to verify average PF
  • Bring 20% more ammo than expected as a buffer

Cost Management for Practice and Competition

Assuming 500 rounds of practice per month and 12 matches per year (approximately 200 rounds each):

Category Quantity Unit Cost Annual Cost
Practice ammo (115gr FMJ) 6,000 rounds ~$0.28 ~$1,680
Match ammo (124gr/150gr) 2,400 rounds ~$0.35 ~$840
Total Annual Ammo Cost 8,400 rounds ~$2,520

Money-Saving Tip: Join a local shooting club — many offer group-buy discounts on ammunition. Also, collect your brass casings. If you start handloading in the future, those casings are a valuable resource.

Introduction to Handloading (Reloading)

Once your shooting volume reaches a certain level, handloading becomes a worthwhile option to consider.

What Is Handloading?

Handloading is the process where shooters purchase individual components — casings, primers, powder, and bullets — and assemble them into complete cartridges using specialized equipment. This process requires precise measurement and strict safety protocols.

Advantages of Handloading

1. Long-term Cost Savings

For 9mm, handloaded ammunition costs approximately $0.12-0.18 per round (using recycled brass), compared to $0.28-0.40 for factory ammo — significant savings over time.

2. Custom Ammunition

You can precisely adjust bullet weight, powder charge, and overall length (OAL) to find the most accurate and reliable recipe for your specific firearm.

3. Precise Power Factor Control

Competitive shooters can fine-tune their Power Factor, using the minimum powder charge that still meets the threshold for the lightest possible recoil.

4. Supply Independence

During ammunition shortages, shooters with reloading capabilities remain unaffected.

Initial Investment for Handloading

Equipment Price Range Notes
Progressive Press $500-1,500 Dillon 550/750, Hornady Lock-N-Load
Die Set $30-80 One set per caliber
Powder Scale $30-100 Digital scales are more precise
Caliper $20-50 For measuring overall length
Other Tools $50-200 Depriming tools, case cleaner, etc.
Total Initial Investment $650-1,900

When Is Handloading Worth It?

A simple break-even calculation:

  • Savings per round with handloading: ~$0.15 (vs. factory practice ammo)
  • Initial equipment investment: ~$800 (mid-range setup)
  • Break-even point: $800 / $0.15 = approximately 5,300 rounds

If you shoot 500+ rounds per month, you’ll recover equipment costs in about 10-11 months. Every round after that is pure savings.

Handloading Safety Guidelines

Handloading requires a serious attitude and proper knowledge. These safety rules must never be overlooked:

  1. Always reference loading manuals: Use verified powder recipes and never exceed the recommended maximum charge
  2. Work up loads gradually: Start at the suggested minimum charge and increase incrementally to your desired Power Factor
  3. Inspect every round: Watch for double charges — this can cause catastrophic failure
  4. Use quality components: Never use deformed or cracked casings
  5. Maintain a clean workspace: Don’t get distracted while loading, and never consume alcohol

Read more: Learn about firearm maintenance to ensure your handgun safely handles various ammunition in our Pistol Cleaning & Maintenance Complete Guide.

Ammunition Storage and Safety

Proper ammunition storage is both a safety concern and affects ammunition reliability and lifespan.

Storage Environment Requirements

Condition Recommendation Reason
Temperature 15-25°C (room temperature) High heat accelerates powder degradation
Humidity Below 60% Moisture damages primers and powder
Light Avoid direct sunlight UV affects powder stability
Container Original packaging or ammo cans Prevents impact damage and moisture

Ammunition Safety Rules

  1. Store separately: Ammunition and firearms should be stored apart, especially in homes with children
  2. Lock it up: Use locked ammunition boxes or safes
  3. First in, first out: Use older ammunition first
  4. Regular inspection: Check ammunition appearance; discard any with oxidation, discoloration, or dents
  5. Transport safely: When heading to the range, keep ammunition in dedicated containers, separate from firearms

Ammunition Shelf Life

Modern factory ammunition stored properly can last 10+ years. However, it’s recommended to:

  • Use practice ammo within 2-3 years of purchase
  • Rotate defensive ammunition annually (use the old ammo for practice)
  • Use handloaded ammunition within 1 year

Ammunition Knowledge for Airsoft Players

While airsoft uses BB pellets rather than live ammunition, understanding real ammunition is valuable for airsoft players — especially if your GBB pistol is a replica of a real firearm.

BB Weight Selection Guide

BB Weight Use Case Notes
0.20g Indoor CQB Standard weight, fast velocity
0.25g General purpose Balance of accuracy and range
0.28-0.30g Outdoor Less wind drift, stable trajectory
0.32-0.40g Sniping Most stable long-range trajectory

Quality Selection Tips:

  • Choose reputable brands (BLS, G&G, Tokyo Marui)
  • Avoid cheap BBs with rough surfaces — they can damage your inner barrel
  • Use biodegradable BBs (Bio BBs) at outdoor fields to protect the environment

Read more: Learn more about airsoft equipment in our Complete Airsoft Gear Selection Guide.

Using a Shot Timer for Ammunition Testing

A Shot Timer isn’t just for training — it’s also a powerful tool for objectively comparing ammunition performance.

Testing Ammunition Impact on Shooting Performance

Using Shot Timer data, you can objectively compare how different ammunition affects your shooting:

Testing Method:

  1. Split Time Comparison

    • Use the same gun with different brands/weights of ammunition
    • Run Bill Drills (6 rapid shots at one target from 7 yards)
    • Record average split times for each ammunition type
    • Lower-recoil ammunition typically produces faster split times

  2. First Shot Time Comparison

    • Test how different ammunition affects your draw-to-first-shot time (usually minimal difference)
    • Focus on observing your mental response to different recoil levels

  3. Accuracy Testing

    • Shoot precision groups at 15-25 yards
    • Record group sizes for different ammunition types
    • Some pistols show better accuracy with specific bullet weights

Example Test Data:

Ammunition Bill Drill Avg Split 25yd 5-shot Group
115gr FMJ 0.22 sec 4.5 inches
124gr FMJ 0.20 sec 3.8 inches
147gr FMJ 0.19 sec 3.2 inches
150gr Syntech 0.18 sec 3.5 inches

The above data is illustrative only — actual performance varies by firearm and shooter. However, the trend is typically consistent: heavier bullets provide softer recoil impulse during rapid fire, enabling faster recovery times.

Frequently Asked Questions (FAQ)

Q1: What caliber should beginners choose?

9mm is the best choice for beginners. Mild recoil, affordable ammunition, wide gun selection, and compatibility with most competitive shooting divisions. Once you develop deeper shooting knowledge, you can consider other calibers.

Q2: Can I use the cheapest ammo for practice?

Yes, but ensure the ammunition comes from reputable brands. Unknown ultra-cheap brands may have quality issues (misfires, inconsistent velocity) or could even damage your handgun. Recommended brands include Magtech, S&B, Federal American Eagle, and similar.

Q3: Can +P ammunition be used in all 9mm pistols?

No. While most modern pistols (Glock, SIG P320, CZ Shadow 2) are rated for +P ammunition, you should verify with the manufacturer’s specifications first. Prolonged heavy use of +P ammunition accelerates parts wear — it’s best reserved for defensive applications.

Q4: Why did my ammo fail the match chrono?

Common reasons include:

  • Temperature effects: Cold weather reduces velocity. If your PF barely clears the minimum, low temperatures could drop you below the threshold
  • Chronograph variance: Different chronographs may show slight reading differences
  • Lot-to-lot variance: Even within the same brand, different production lots may have velocity variations

It’s recommended to re-chrono close to match day to confirm.

Q5: Can I use steel-cased ammunition?

Steel-cased ammunition (Tula, Wolf, etc.) is cheaper but has several drawbacks:

  • Cannot be reloaded
  • May accelerate extractor wear in some pistols
  • Prohibited at some indoor ranges
  • Cannot be used for handloading

If you’re only doing casual practice and don’t plan to collect brass, steel-cased ammo is an acceptable budget option.

Q6: How much ammo should I bring to a match?

A typical IPSC/USPSA match requires 150-200 rounds (depending on the number of stages). It’s recommended to bring 30-50% more than needed to account for makeups, reshoots, or extra practice. Bringing 250 rounds to a standard Level 1 match is a safe amount.

Q7: How do I choose BB weight for airsoft?

It mainly depends on your gun and use case:

  • Indoor CQB: 0.20-0.25g (short range, lighter is fine)
  • Outdoor general: 0.25-0.28g (balanced accuracy and range)
  • Outdoor precision: 0.28-0.32g (more stable trajectory)
  • Sniping: 0.36-0.40g (maximum range and accuracy)

Your Hop-up system will also need adjustment based on BB weight.

Q8: How do I tell if ammunition has gone bad?

Check for these signs:

  • Visible oxidation on the casing (green corrosion or white powder)
  • Loose or misaligned bullet
  • Primer dents or corrosion
  • Casing cracks or deformation
  • If you notice any of these conditions, do not use that ammunition

Conclusion

Ammunition selection may seem straightforward, but it actually involves physics, materials science, and competition rules across multiple dimensions. For most shooters, mastering these core principles is sufficient:

  1. Beginners: choose 9mm — affordable, easy to learn with, widest applicability
  2. Practice with quality ammo — choose reputable brands; don’t risk quality issues to save a few cents
  3. Chrono before matches — ensure your ammo meets Power Factor with margin to spare
  4. Consider long-term costs — high-volume shooters should consider handloading

Remember, the best ammunition is ammunition you can afford to practice with in volume. The most expensive match ammo in the world is counterproductive if it makes you reluctant to practice.