A 13B Cannon Crewmember is the backbone of the United States Army’s Field Artillery branch, often referred to as the "King of Battle." These Soldiers are responsible for operating and maintaining heavy artillery systems, primarily howitzers, to provide devastating indirect fire support for infantry and armored units. The role is a Military Occupational Specialty (MOS) that demands high physical strength, mental resilience under pressure, and technical precision.

To become a 13B, a recruit must typically score a 93 in the Field Artillery (FA) category of the ASVAB, complete 10 weeks of Basic Combat Training, and undergo specialized training at Fort Sill, Oklahoma. The job involves everything from manually loading 100-pound projectiles to using advanced digital fire-control systems to strike targets miles away.

Core Responsibilities of the 13B MOS

The duties of a 13B Cannon Crewmember extend far beyond simply pulling a lanyard. The role is multifaceted, requiring a blend of mechanical skill, teamwork, and tactical awareness.

Operating and Firing Howitzer Systems

The primary mission of a 13B is to deliver fires. This involves a synchronized sequence of events performed by a section of Soldiers. Crewmembers are responsible for:

  • Setting Fuses and Charges: Artillery rounds are not "one size fits all." Crewmembers must set the correct fuse (point detonating, delay, or proximity) and prepare the propellant charges based on the distance to the target.
  • Loading the Breech: Whether operating a towed M777 or a self-propelled M109 Paladin, the crew must ram the projectile into the tube and insert the propellant and primer with speed and accuracy.
  • Laying the Piece: Using computer-generated data from the Fire Direction Center (FDC), the gunner and crew adjust the elevation and deflection (horizontal direction) of the cannon tube to ensure the round lands precisely where intended.

Ammunition Management and Logistics

Artillery is a hungry beast that requires constant feeding. A significant portion of a 13B’s job involves the heavy lifting of ammunition.

  • Handling and Storage: Crewmembers manage various types of munitions, including high-explosive (HE), white phosphorus (smoke), illumination, and precision-guided projectiles like the Excalibur.
  • Safety Protocols: Handling explosives requires strict adherence to safety regulations to prevent accidents during transport and firing.
  • Accountability: Maintaining an accurate count of rounds fired and propellant used is critical for tactical resupply and mission planning.

Vehicle Operation and Maintenance

13B Soldiers are also responsible for the platforms that carry the cannons.

  • Towed Artillery: Crewmembers drive and maintain prime movers (heavy trucks) that tow systems like the M777 or M119.
  • Self-Propelled Artillery: Those assigned to M109 Paladin units must maintain the tracked vehicle's engine and chassis, which is essentially a massive armored tank with a cannon.
  • Preventative Maintenance Checks and Services (PMCS): Daily maintenance is a way of life. Ensuring the hydraulic systems, breech blocks, and engine components are functional is the difference between mission success and equipment failure.

The Hardware of Field Artillery

Understanding the 13B role requires looking at the specific weapons systems they master. Each system offers a different experience and set of challenges.

M109A6/A7 Paladin

The Paladin is a self-propelled 155mm howitzer. For a 13B, this means working inside an armored hull. It is highly automated compared to towed systems, featuring on-board navigation and fire-control systems that allow it to "shoot and scoot"—firing a round and moving to a new location before enemy radar can track the origin of the shot.

M777 Lightweight Towed Howitzer

The M777 is the workhorse of the Marine Corps and Army light infantry divisions. Because it is made of titanium, it is light enough to be transported by helicopter. For the 13B, this system is much more physically demanding, as it requires manual "emplacement" (setting the spades into the ground) and manual loading without the aid of the Paladin's automated rammers.

M119 105mm Howitzer

This is a smaller, more mobile cannon used primarily by airborne and air assault units. The rounds are lighter, but the rate of fire is often higher, requiring the crew to move with extreme speed and agility during high-intensity fire missions.

Training Pipeline for 13B Cannon Crewmembers

The journey to becoming a qualified 13B involves two distinct phases of training designed to transform a civilian into a tactical expert.

Phase 1: Basic Combat Training (BCT)

Before learning the specifics of artillery, every recruit must complete 10 weeks of BCT. This phase focuses on:

  • Physical fitness and the Army Combat Fitness Test (ACFT).
  • Marksmanship with the M4 carbine.
  • Warrior tasks and battle drills.
  • Discipline, customs, and courtesies of the Army.

Phase 2: Advanced Individual Training (AIT) at Fort Sill

Upon graduating BCT, 13B recruits head to Fort Sill, Oklahoma, for 5 to 7 weeks of AIT. This is where the specialized "gunnery" training occurs.

Week 1-2: Integration and Fundamentals

Recruits are introduced to the field artillery culture. They learn the history of the branch and begin initial training on radio communications and the Basic Life Saver (BLS) course. A major focus is the High Physical Demands Test (HPDT), which ensures the Soldier can handle the weight of artillery rounds.

Week 3-4: Ammunition and Maintenance

The focus shifts to the technical aspects of the job. Recruits learn to identify different types of shells and fuses. They are taught how to perform maintenance on the various howitzer systems, learning how to disassemble and clean the breech block and check hydraulic fluid levels.

Week 5-6: Live Fire and Certification

The culmination of AIT is the live-fire exercise. Recruits occupy actual firing positions in the Oklahoma hills. They practice "fire missions," where they receive data from an FDC and must load and fire real high-explosive rounds. Upon successful completion, they earn the right to be called an Artilleryman.

Qualifications and Physical Requirements

The 13B MOS is not available to everyone; it has specific cognitive and physical benchmarks that must be met.

ASVAB Score Requirements

The Armed Services Vocational Aptitude Battery (ASVAB) determines a recruit's eligibility for specific jobs. For a 13B, the Army looks at the Field Artillery (FA) line score.

  • Minimum Score: A score of 93 in the FA category is generally required.
  • Components: The FA score is calculated from Arithmetic Reasoning (AR), Mathematics Knowledge (MK), and Mechanical Comprehension (MC).

Physical Demands Category

The 13B MOS is officially classified as a "Very Heavy" demand job. This classification is based on the Occupational Physical Assessment Test (OPAT).

  • Lifting: Soldiers must be able to lift and carry 155mm projectiles, which weigh approximately 95 to 103 pounds.
  • Stamina: Crewmembers often operate in extreme weather conditions (heat or cold) for 24 to 72 hours during field rotations.
  • Team Strength: Many tasks, such as "shoveling in" a towed howitzer’s spades, require sustained anaerobic effort.

Medical and Security Standards

  • Color Vision: 13B Soldiers must have normal color vision (no red/green color blindness) to correctly identify ammunition markings and signal flags.
  • Security Clearance: While a Secret clearance is not always required for entry-level 13B Soldiers, those moving into specialized roles or leadership may require one.
  • U.S. Citizenship: Generally, recruits must be U.S. citizens or permanent residents (Green Card holders).

Life in the Field: What the Job is Really Like

To understand the 13B experience, one must look past the recruitment videos. The reality of the job is characterized by noise, dirt, and brotherhood.

The Noise Factor

Artillery is loud. Even with advanced hearing protection, the concussive force of a 155mm round leaving the tube is felt throughout the body. Continuous operations require Soldiers to be vigilant about their hearing and communication protocols.

Reduced Visibility Operations

Field Artillery units do not stop when the sun goes down. 13B Soldiers are trained to operate in total darkness using night vision devices (NVDs). Setting fuses, loading rounds, and navigating heavy vehicles in "blackout" conditions is a core skill set.

The Team Dynamic

A howitzer section is a tight-knit team of 5 to 10 Soldiers. Each member has a specific numbered role (#1 man, #2 man, etc.). Because the speed of fire depends on everyone doing their job perfectly, the bond between 13Bs is often stronger than in many other MOSs. If the loader is slow, the gun doesn't fire; if the gunner is off, the round misses.

Career Progression and Rank Structure

A 13B’s career path moves from hands-on labor to tactical leadership.

  1. Junior Enlisted (PVT to SPC): Focus is on mastering the manual tasks—loading, cleaning, and driving.
  2. Non-Commissioned Officer (SGT to SSG): As a Section Chief, the 13B becomes responsible for the entire gun crew. They verify the firing data, ensure safety protocols are followed, and oversee the maintenance of millions of dollars of equipment.
  3. Senior NCO (SFC to SGM): At higher ranks, a 13B may become a Platoon Sergeant or a First Sergeant, managing multiple gun sections and focusing on the logistics and tactical employment of the entire battery.

Civilian Career Opportunities After the Army

While there are few civilian jobs that involve firing cannons, the skills learned as a 13B are highly transferable to several industries:

  • Heavy Equipment Operation: Mastery of the prime movers and tracked vehicles translates directly to construction and mining.
  • Logistics and Supply Chain: Managing ammunition and equipment maintenance prepared Soldiers for warehouse and fleet management roles.
  • Law Enforcement and Security: The discipline and ability to work under high pressure are highly valued by police departments.
  • Project Management: Senior 13Bs who have led gun sections possess the leadership skills required for supervisory roles in manufacturing or technical fields.

Compensation, Pay, and Benefits for 13B

Soldiers in the 13B MOS are paid based on the standard U.S. Army pay scale, determined by rank and years of service.

Monthly Base Pay Examples (2026 Estimates)

  • E-1 (Private): Starting at approximately $2,226 per month.
  • E-3 (Private First Class): Approximately $2,837 per month.
  • E-5 (Sergeant): Approximately $3,342 per month.

Additional Allowances

Beyond base pay, 13B Soldiers receive:

  • BAH (Basic Allowance for Housing): A tax-free stipend for those living off-post, varying by zip code.
  • BAS (Basic Allowance for Subsistence): A monthly allowance for food.
  • Hazardous Duty Pay: Available during certain deployments or specific training exercises.
  • Enlistment Bonuses: Depending on the Army's needs, 13B recruits may be eligible for bonuses ranging from $5,000 to $16,000.

Educational Benefits

The Montgomery GI Bill or Post-9/11 GI Bill provides full tuition coverage for college after service, along with a monthly housing allowance while attending school.

Frequently Asked Questions about MOS 13B

Is 13B a combat MOS?

Yes. 13B is a combat arms MOS. While they provide indirect fire from a distance, they are often located near the front lines and are trained to defend their positions against ground attacks using rifles and machine guns.

Can women be 13B Cannon Crewmembers?

Yes. Since 2016, all combat MOS positions in the U.S. Army, including 13B, have been open to women who meet the physical and tactical standards.

How loud is the howitzer?

It is extremely loud, reaching levels above 140 decibels. Soldiers are issued tactical earplugs and noise-canceling headsets to mitigate the risk of hearing loss.

Where will I be stationed as a 13B?

Field Artillery units are located at most major Army installations, including Fort Liberty (NC), Fort Bliss (TX), Fort Sill (OK), Fort Campbell (KY), and OCONUS locations like Germany, South Korea, and Hawaii.

Summary of the 13B Cannon Crewmember Path

Choosing the 13B MOS is a commitment to a high-intensity, physically demanding lifestyle. It is a role for those who prefer the outdoors to an office and who want to be part of the Army’s primary strike force. From the grueling weeks at Fort Sill to the adrenaline of a live-fire exercise, the 13B Cannon Crewmember remains a vital component of modern warfare. Whether operating a digital Paladin or a titanium M777, these Soldiers ensure that the Army maintains its battlefield superiority through the precision and power of Field Artillery.