Ammunition Reference Guide: Rifle, Pistol & Shotgun Ammo

Ammunition is available in a wide range of cartridges, projectile designs, weights and load configurations intended for different purposes. Understanding the information printed on an ammunition box can make it much easier to identify, organize and label stored ammunition correctly.

This guide explains common terminology found on rifle, pistol and shotgun ammunition and the information that is most useful when identifying ammunition for storage.

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Ammunition Basics

Cartridge vs. Bullet

The terms cartridge and bullet are often used interchangeably in casual conversation, but they are not the same thing.

A complete rifle or handgun cartridge generally consists of a:

• Cartridge/Case
• Primer
• Propellant (Powder)
• Projectile (Bullet)

Shotgun ammunition is generally referred to as a shotshell or shell and uses somewhat different construction, typically including a hull, primer, propellant, wad and a payload consisting of shot or a slug. Federal identifies these same basic shotshell components in its shotshell anatomy guide.

For ammunition identification, the complete cartridge or shotshell designation tells you what ammunition you have, while information such as bullet type, bullet weight, shot size or load type further distinguishes the specific load.

Rimfire vs. Centerfire

Modern metallic cartridges generally use either rimfire or centerfire ignition.

Rimfire ammunition contains priming compound within the rim of the cartridge case. Common examples include .22 Long Rifle (22 LR), .22 WMR and .17 HMR.

Centerfire ammunition uses a separate primer located in the center of the cartridge case head. Most modern rifle and handgun cartridges larger than common rimfire cartridges use centerfire primers.

SAAMI maintains separate current standards for rimfire, centerfire pistol/revolver, centerfire rifle and shotshell ammunition.

For storage and identification, the exact cartridge designation is generally more useful than identifying whether the ammunition is rimfire or centerfire.

Understanding Grain Weight – GR

Projectile weight for rifle and handgun ammunition is commonly expressed in grains, abbreviated GR or gr.

A grain is a unit of weight. When an ammunition box lists a value such as 55 GR, 124 GR or 168 GR, it normally describes the weight of the projectile—not the amount of propellant contained in the cartridge.

The same cartridge may be available with many different bullet weights, making grain weight an important identifier.

For example:  .308 WIN | SP | 150 GR  and  .308 WIN | OTM | 175 GR are both 308 Winchester ammunition but represent distinctly different loads.

Shotgun ammunition may use several different weight conventions. Shot payloads are commonly identified in ounces, while slugs may be listed in either ounces or grains. Buckshot packaging may additionally identify the number of pellets. Winchester specifically notes that shotshell payload weight is normally listed in ounces while buckshot commonly uses pellet count.

Common Bullet Construction Terms

Many bullet constructions appear in both rifle and handgun ammunition, so these terms are defined here rather than repeated in each section.

FMJ – Full Metal Jacket

A bullet in which a metal jacket encloses most of the bullet's core. FMJ ammunition is commonly associated with target shooting, training and general range use.

SP – Soft Point

A jacketed bullet with exposed lead at the nose. Soft-point bullets are commonly found in hunting ammunition designed to provide expansion.

HP – Hollow Point

A bullet containing an opening or cavity in its nose. The designation alone does not necessarily indicate the bullet's intended application; hollow- or open-tip designs can be used in hunting, defensive and precision ammunition depending on their construction.

POLYMER TIP / TIPPED

A bullet containing a polymer tip in the nose. Polymer-tipped bullets are available in hunting, varmint, match and other specialized designs, so the presence of a tip alone does not determine the bullet's intended use.

BONDED

A jacketed bullet in which the core and jacket are bonded together to help resist separation during impact. Bonded construction is frequently found in hunting and defensive ammunition.

MONOLITHIC / COPPER / LEAD-FREE

A projectile manufactured primarily from one material or alloy rather than a conventional lead core surrounded by a separate jacket. Copper and copper-alloy bullets are common examples.

FRANGIBLE

A projectile designed to break into smaller fragments when it strikes a sufficiently hard surface. Frangible ammunition is commonly associated with specialized training and reduced-ricochet applications.

RN – Round Nose

A projectile with a rounded nose profile.

FN / FP – Flat Nose / Flat Point

A projectile with a flattened nose profile.

Reading an Ammunition Label

A typical rifle or handgun ammunition box might read:  5.56×45 NATO | FMJ | 62 GR

This identifies:

• 5.56×45 NATO – Cartridge designation
• FMJ – Bullet construction
• 62 GR – Bullet weight

For most rifle and handgun ammunition, three of the most useful identification fields are:  Cartridge | Bullet Type | Bullet Weight

Additional information such as +P, SUBSONIC, MATCH, LEAD-FREE or a manufacturer-specific bullet designation can be added when it meaningfully distinguishes one load from another.

Shotgun labels use somewhat different identifying information, which is covered in the Shotgun Ammunition section below.

Manufacturer-Specific Names

Ammunition manufacturers frequently use proprietary names in addition to standard terms such as FMJ, JHP, OTM or SP.

For ammunition organization, prioritize the information needed to distinguish the load:

• Exact cartridge or gauge
• Projectile or load type
• Bullet weight, shot size or slug weight
• Special designation such as +P, Subsonic or TSS
• Manufacturer or product line when needed for additional identification

You generally do not need to reproduce every word printed on the ammunition box.

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Rifle Ammunition

Understanding Rifle Cartridge Names

Rifle cartridge names use several different naming conventions. Traditional inch-based examples include:

• .223 Remington
• .243 Winchester
• .270 Winchester
• .308 Winchester
• .30-30 Winchester
• .30-06 Springfield
• .300 Winchester Magnum

Metric examples include:

• 5.56×45 NATO
• 6.5×55 Swedish
• 7.62×39
• 7.62×51 NATO
• 7.62×54R

Metric cartridge designations frequently combine the approximate projectile diameter and case length in millimeters, with additional names or designations used to differentiate cartridges.

Modern commercial examples include:

• 6.5 Creedmoor
• 6.5 PRC
• .300 AAC Blackout / 300 BLK
• .350 Legend
• .450 Bushmaster

The numerical caliber alone does not uniquely identify a cartridge. Different cartridges may use bullets of similar diameter while having different case dimensions, chamber specifications and operating characteristics.

For identification and storage, use the complete cartridge designation whenever possible.

Common Rifle-Specific Bullet Types & Abbreviations

BT – Boat Tail

A Boat Tail bullet has a tapered rear section rather than a conventional flat base. The tapered profile is intended to reduce aerodynamic drag. Boat-tail construction is commonly combined with other bullet types.

Examples:

• FMJ-BT / FMJBT – Full Metal Jacket Boat Tail
• BTHP / HPBT – Boat-Tail Hollow Point

BTHP / HPBT – Boat-Tail Hollow Point

A projectile combining a hollow or open nose with a tapered boat-tail base.

BTHP bullets are widely associated with match and precision rifle ammunition.

The hollow-point appearance should not automatically be interpreted as meaning the bullet is designed to expand like a conventional hunting or defensive hollow point.

OTM – Open Tip Match

An Open Tip Match projectile has a small opening at the nose resulting from the bullet's manufacturing process.

OTM ammunition is primarily associated with accuracy, target and match applications rather than conventional expanding hollow-point construction.

PSP – Pointed Soft Point

A Pointed Soft Point is a soft-point hunting bullet with a more aerodynamic pointed profile than a traditional round-nose soft point. Manufacturer terminology for similar designs may vary.

MATCH / MATCH GRADE

A general designation for ammunition manufactured with an emphasis on consistency and accuracy. Match ammunition may use:

• OTM
• BTHP / HPBT
• Tipped match bullets

“Match” describes the intended performance category rather than one specific bullet construction.

Common Rifle Ammunition Applications

TARGET / RANGE / TRAINING

General-purpose ammunition intended primarily for practice and recreational target shooting. FMJ and FMJ-BT projectiles are common in this category.

MATCH / PRECISION

Ammunition manufactured with an emphasis on accuracy and consistency. Common projectile descriptions include:

• OTM
• BTHP / HPBT
• MATCH

HUNTING

A broad ammunition category containing projectile designs intended for hunting. Common constructions include:

• Soft Point
• Bonded
• Polymer-Tipped
• Monolithic Copper / Lead-Free

Actual projectile construction and recommended application vary considerably by cartridge and manufacturer.

VARMINT / PREDATOR

Ammunition commonly using lighter or rapidly expanding bullets intended for varmint, predator or similar hunting applications.

Polymer-tipped and specialized hollow-point bullets are frequently encountered in this category.

DEFENSE / DUTY

Rifle ammunition specifically marketed for defensive or law-enforcement use.

Because designs vary significantly between manufacturers, retaining the manufacturer's specific projectile designation can be useful when labeling these loads.

SUBSONIC

A designation used for ammunition intended to operate below the speed of sound under specified conditions.

Subsonic ammunition is available for certain rifle cartridges and is usually identified prominently on the packaging.

Common Rifle Ammo Label Examples

• .223 REM | FMJ | 55 GR
• 5.56 NATO | FMJ | 62 GR
• .308 WIN | SP | 150 GR
• .308 WIN | BTHP MATCH | 168 GR
• .308 WIN | OTM | 175 GR
• 6.5 CREEDMOOR | BTHP | 140 GR
• .300 BLK | SUBSONIC | 220 GR

Cartridge Names & Common Abbreviations

Some rifle cartridges are commonly identified using shortened names:

• .223 Remington → .223 Rem
• .308 Winchester → .308 Win
• .300 Winchester Magnum → .300 Win Mag
• .300 AAC Blackout → .300 BLK
• .30-06 Springfield → .30-06 Sprg
• .22 Long Rifle → .22 LR

Abbreviations can be useful for compact labels, but abbreviated or similar names should not be used to assume that differently designated cartridges are interchangeable.

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Pistol & Handgun Ammunition

Pistol and handgun ammunition includes cartridges used in semi-automatic pistols, revolvers and other handgun platforms.

The same general ammunition concepts covered above apply, but handgun ammunition has several distinctive cartridge names, pressure designations and projectile styles useful for identification.

Understanding Handgun Cartridge Names

Common handgun cartridges include:

• .380 Auto
• 9mm Luger
• .357 SIG
• .40 S&W
• 10mm Auto
• .45 Auto
• .38 Special
• .357 Magnum
• .44 Special
• .44 Magnum
• .45 Colt

Terms such as Auto, Special, Magnum, SIG and S&W are part of the actual cartridge designation, not descriptions of the bullet.

That distinction matters when creating compact ammunition labels.

For example: .357 MAG is much more useful than simply .357.

Likewise: .38 SPL provides substantially more identification than simply .38.

Common semi-automatic pistol cartridges include .380 Auto, 9mm Luger, 10mm Auto, .40 S&W and .45 Auto, while cartridges such as .38 Special, .357 Magnum, .44 Special and .44 Magnum are strongly associated with revolvers.

The firearm platform itself should never be used to determine ammunition compatibility; the exact cartridge designation remains the important identifier.

Understanding +P Ammunition

Some handgun ammunition includes a +P designation.

+P identifies a standardized higher-pressure version of certain cartridges. Current SAAMI pistol and revolver standards recognize +P specifications for cartridges including 9mm Luger +P, .38 Special +P, .38 Super Auto +P and .45 Auto +P.

Because +P represents a meaningful difference in the ammunition specification, it should be preserved when labeling stored ammunition.

For example:  9mm LUGER | JHP | 124 GR and 9mm LUGER | JHP +P | 124 GR should be treated as distinct loads.

Common Handgun-Specific Bullet Types

TMJ – Total Metal Jacket

A Total Metal Jacket projectile encloses the lead core more completely than a conventional FMJ, including the bullet base.

TMJ ammunition is commonly used for target and training applications and is frequently marketed for reducing exposed lead during shooting.

Typical label:  9mm LUGER | TMJ | 124 GR

JHP – Jacketed Hollow Point

A Jacketed Hollow Point uses a jacketed projectile with a cavity in the nose. JHP ammunition is particularly common in personal-defense and duty handgun ammunition.

Typical label:  9mm LUGER | JHP | 124 GR

Some JHP bullets also incorporate bonded cores, polymer inserts or other manufacturer-specific construction.

SJHP – Semi-Jacketed Hollow Point

A Semi-Jacketed Hollow Point leaves part of the lead nose exposed around the hollow cavity. This design is frequently encountered in traditional revolver ammunition and some hunting loads.

Typical label:  .357 MAG | SJHP | 158 GR

JSP – Jacketed Soft Point

A Jacketed Soft Point uses a jacket around much of the projectile while leaving exposed lead at the nose. JSP bullets are commonly encountered in revolver, hunting and general-purpose handgun loads.

Typical label:  .357 MAG | JSP | 158 GR

WC – Wadcutter

A Wadcutter uses a broad, flat-fronted projectile profile intended to produce a clean hole in paper targets. Wadcutters are especially associated with precision revolver target ammunition.

Typical label:  .38 SPL | WC | 148 GR

SWC – Semi-Wadcutter

A Semi-Wadcutter combines a flat nose and distinct shoulder with a more tapered forward profile than a full wadcutter. SWC ammunition is commonly associated with target and competition shooting as well as some hunting and general-purpose loads.

Typical label:  .45 AUTO | SWC | 185 GR

LRN – Lead Round Nose

A Lead Round Nose projectile uses exposed lead with a rounded nose profile. LRN bullets are commonly encountered in traditional target and practice ammunition.

Typical label:  .38 SPL | LRN | 158 GR

HARD CAST

Hard Cast describes a projectile made from a hardened lead alloy rather than a conventional jacketed construction. Hard-cast handgun ammunition is commonly associated with hunting, outdoor and specialized loads where manufacturers emphasize penetration and projectile durability.

Common package descriptions may include:

• HARD CAST
• HARD CAST FLAT NOSE
• HC-FN
• WFN – Wide Flat Nose

Because manufacturer terminology varies, retaining the original projectile designation is useful.

Common Handgun Ammunition Applications

TARGET / RANGE / TRAINING

Common projectile types include:

• FMJ
• TMJ
• WC
• SWC
• LRN

DEFENSE / PERSONAL PROTECTION

JHP and other specialized expanding bullets are commonly used in ammunition marketed for defensive purposes. Because proprietary bullet designs are common in this category, manufacturer-specific names can provide useful additional identification.

DUTY / LAW ENFORCEMENT

Duty ammunition frequently uses specialized or bonded JHP designs intended to meet manufacturer- or agency-specific performance requirements.

COMPETITION / MATCH

Competition ammunition may use FMJ, wadcutter, semi-wadcutter or other specialized projectile designs depending on the shooting discipline.

HUNTING / BACKCOUNTRY

Handgun ammunition marketed for hunting or outdoor use may use:

• JSP
• JHP
• Bonded bullets
• Hard-cast bullets
• Monolithic or solid projectiles

Common Handgun Ammo Label Examples

• 9mm LUGER | FMJ | 115 GR
• 9mm LUGER | JHP | 124 GR
• 9mm LUGER | JHP +P | 124 GR
• .380 AUTO | FMJ | 95 GR
• .45 AUTO | FMJ | 230 GR
• .45 AUTO | SWC | 185 GR
• .38 SPL | WC | 148 GR
• .357 MAG | JSP | 158 GR

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Shotgun Ammunition

Shotgun ammunition differs substantially from conventional rifle and handgun cartridges. Instead of identifying ammunition primarily by cartridge caliber, bullet design and grain weight, shotshells are commonly distinguished by:

Gauge or Bore | Shell Length | Load Type | Shot Size or Slug Weight | Shot Material

Federal's current shotshell catalog uses these same types of fields, including gauge, shell length, shot size, shot weight, material and application.

Understanding Gauge & Bore

Most shotgun ammunition is identified by gauge, such as:

• 10 Gauge
• 12 Gauge
• 16 Gauge
• 20 Gauge
• 28 Gauge

The .410 Bore is commonly grouped with shotgun gauges but uses a bore-diameter designation rather than the traditional gauge naming system.

For ammunition identification, always retain the complete gauge or bore designation.

Examples:

• 12 GA
• 20 GA
• 28 GA
• .410 BORE

Understanding Shotshell Length

Shotshell length is an important part of shotgun ammunition identification.

Common shell lengths include:

• 1-3/4" - A short or “mini” shotshell length available in selected loads and firearm configurations.
• 2-1/2" - Commonly encountered in certain gauges and especially in some .410 Bore ammunition.
• 2-3/4" - One of the most widely used general-purpose shotshell lengths and available across target, hunting, buckshot and slug ammunition.
• 3" - A longer shotshell commonly used for loads requiring additional payload capacity, including many hunting, waterfowl, turkey, buckshot and slug loads.
• 3-1/2" - An extra-length shotshell primarily associated with heavy hunting loads, particularly turkey and waterfowl ammunition.

Federal currently lists commercial shotshells ranging from approximately 1¾ inches through 3½ inches, depending on gauge and load.

Longer shell length does not by itself tell you everything about a load's performance. Payload weight, projectile type, velocity and other load specifications also matter.

Because shell length is part of firearm compatibility, always match the shotshell length to the shotgun's chamber specifications.

Understanding Shot Payload Weight

Shotshells loaded with multiple pellets commonly list the total shot payload in ounces.

Examples include:

• 3/4 OZ
• 7/8 OZ
• 1 OZ
• 1-1/8 OZ
• 1-1/4 OZ

A heavier payload generally contains more shot material, although the actual pellet count depends on shot size and material. For ammunition storage, payload weight can be useful when you have several otherwise similar loads.

Example:  12 GA | 2-3/4" | #8 | 1 OZ  vs.  12 GA | 2-3/4" | #8 | 1-1/8 OZ

Birdshot

Birdshot is the broad term commonly used for shotshell loads containing numerous relatively small pellets.

Despite the name, these loads cover far more than bird hunting and are used for:

• Clay targets
• Dove / Quail
• Upland hunting
• Small game
• Turkey
• Waterfowl

Federal notes that the term birdshot is commonly used broadly for shot sizes smaller than buckshot, including pellets used for targets, turkey and waterfowl.

Understanding Shot Size

With conventional numbered shot, the larger the shot number, the smaller the individual pellet.

For example:

• #9 is smaller than #8
• #8 is smaller than #6
• #6 is smaller than #4

Shot sizes do not define one mandatory application, but common examples include:

#9, #8 and #7-1/2

Frequently found in:

• Trap / Skeet / Sporting Clays
• Target loads
• Dove
• Quail

Federal currently offers #7.5 and #8 shot specifically in competition and target loads and #7.5 in upland/quail ammunition.

#7-1/2, #6 and #5

Frequently encountered in:

• Upland hunting
• Pheasant
• Grouse
• Rabbit
• Squirrel

Federal currently offers upland loads in #7.5, #6 and #5 depending on gauge and intended application.

#4, #3 and #2

Commonly encountered in larger-gamebird and waterfowl loads, particularly when using steel shot. Winchester currently offers steel waterfowl loads in #4, #3 and #2 as well as other sizes.

#1, BB, BBB and T

Larger shot sizes commonly encountered in loads intended for larger waterfowl and specialized applications.

Turkey Shot

Traditional turkey ammunition frequently uses relatively large lead shot, while modern high-density tungsten-based loads can use substantially smaller pellets. For example, Federal currently offers TSS turkey ammunition using #7 and #9 tungsten shot, including blended #7/#9 loads.

Shot size recommendations should therefore always be considered together with the shot material and specific load design.

Shot Materials

Shotshell pellets may be manufactured from several materials.

LEAD

Traditional material used in many target, upland, turkey and small-game loads where permitted.

STEEL

A common non-toxic shot material widely used in waterfowl ammunition.

BISMUTH

A denser non-toxic alternative to steel used in hunting ammunition.

TUNGSTEN / TSS

High-density tungsten-based shot used in specialized hunting ammunition, particularly premium turkey and waterfowl loads. Federal identifies steel, bismuth and tungsten as the primary modern non-toxic shot options and notes their substantially different densities.

Because pellet material affects pellet mass and performance, the same numerical shot size should not automatically be considered equivalent across different materials.

Buckshot

Buckshot uses a smaller number of substantially larger pellets than conventional birdshot.

Common buckshot designations include:

• #4 BUCK
• #3 BUCK
• #2 BUCK
• #1 BUCK
• 0 BUCK
• 00 BUCK – “Double-Ought”
• 000 BUCK – “Triple-Ought”

Unlike ordinary numbered birdshot, buckshot uses its own sizing convention. Shotshell packaging commonly identifies both the buckshot size and pellet count.

An ammo label example may look something like: 12 GA | BUCKSHOT | 2-3/4" | 00

Buckshot is commonly encountered in ammunition marketed for deer, predator and defensive applications, depending on local regulations and the specific load. Federal currently categorizes commercial 00 Buck shotshells for applications including self-defense.

Slugs

A slug replaces the multiple-pellet payload with a single large projectile.

Shotgun slugs are commonly identified by:

• Gauge
• Shell length
• Slug type
• Projectile weight

Slug weight may be expressed in either ounces or grains.

For reference:  1 oz ≈ 438 grains

A common label might therefore read:  12 GA | SLUG | 2-3/4" | 1 OZ

Federal currently lists a 12-gauge 2¾-inch rifled slug at approximately 438 grains / 1 ounce.

RIFLED / FOSTER-STYLE SLUG

Rifled-style slugs are commonly intended for use with smoothbore shotgun barrels.

Federal specifically identifies its current Power-Shok rifled slug as designed for smoothbore barrels.

SABOT SLUG

A sabot slug uses a smaller projectile carried within a surrounding sabot or sleeve.

Sabot slugs are typically intended for fully rifled shotgun barrels and are commonly used in hunting applications where increased slug accuracy is desired.

Federal specifies fully rifled barrels for its current Power-Shok sabot slug.

Because rifled slugs and sabot slugs are designed around different barrel configurations, retaining RIFLED SLUG or SABOT on the ammunition label is useful.

Popular Shotgun Ammo Types & Applications

BUCKSHOT

Loads containing multiple large pellets. Commonly associated with deer, predator and defensive applications.

BIRDSHOT

A broad category containing numerous smaller pellets and covering target, upland, small-game, turkey and waterfowl loads.

SLUG

A single-projectile shotshell commonly used for deer and other big-game applications where permitted.

SABOT

A specialized slug configuration generally intended for rifled shotgun barrels.

TURKEY

Purpose-built hunting ammunition designed to produce dense patterns. Loads may use traditional lead pellets or high-density tungsten/TSS shot.

DOVE / QUAIL

Typically, lighter bird loads using relatively small shot such as #7½, #8 or similar sizes.

UPLAND

Loads intended for pheasant, grouse, quail and other upland birds. Common shot sizes vary considerably with game species and shot material.

SMALL GAME

Loads commonly marketed for rabbit, squirrel and similar game.

WATERFOWL

Loads intended for ducks, geese and other waterfowl. Steel, bismuth and tungsten-based non-toxic shot are commonly used.

DEER

May include rifled slugs, sabot slugs or buckshot, depending on the firearm, load and applicable hunting regulations.

DEFENSE

Shotshells marketed specifically for defensive applications, with buckshot being one of the most common load types.

TARGET

Loads intended for trap, skeet, sporting clays and general target shooting.

 

Common Shotgun Ammo Label Examples

• 12 GA | 2-3/4" | #8 | TARGET
• 12 GA | 2-3/4" | #7-1/2 | DOVE
• 20 GA | 2-3/4" | #6 | UPLAND
• 12 GA | 3" | #2 STEEL | WATERFOWL
• 12 GA | 3-1/2" | BB STEEL | WATERFOWL
• 12 GA | 3" | #9 TSS | TURKEY
• 12 GA | 2-3/4" | 00 BUCK | 9 PELLET
• 12 GA | 2-3/4" | 1 OZ | RIFLED SLUG
• 12 GA | 2-3/4" | 438 GR | SABOT

For shotgun ammunition, the most useful identifying information is generally:

Gauge | Shell Length | Load Type | Shot Size / Slug Weight

Additional information such as shot material, payload weight, pellet count or application can be added when it helps distinguish otherwise similar loads.

Ammunition Identification & Compatibility - A Note on Safety

Similar-looking ammunition—or ammunition containing similar caliber numbers—is not automatically interchangeable.

Use the complete ammunition designation shown by the manufacturer when identifying stored ammunition and always verify compatibility against the firearm manufacturer's chamber markings, owner's manual and recommendations.

SAAMI specifically maintains ammunition and chamber standards to address dimensional, pressure, safety and interchangeability requirements.

This guide is intended as a general reference for ammunition identification, terminology and organization and is not a substitute for firearm or ammunition manufacturer instructions.