Shotgun Patterning & Choke Selection Guide: Technical Performance Tips

From the Bench: A gunsmith's journey into shotgun mechanics

By Hootey Cline, Blue Coat Arms Company

Originally published June 14, 2019 | Updated July 2, 2025

Here in Illinois, 70% of all hunting is done with shotguns – yet I'm constantly amazed by how many hunters use these tools without truly understanding how they work or how to optimize their performance. After years of working on shotguns and talking with countless hunters, I've learned that there's much more to these versatile firearms than most people realize.

Let me share what I've discovered about shotgun mechanics and performance optimization, always with the understanding that I'm still learning something new about these fascinating firearms with every project that comes through the shop.

How Shotgun Patterning Works: Multiple Projectile Performance

Understanding the Shotgun Concept

Shotguns shoot multiple projectiles at a time – this is what makes them fundamentally different from rifles and handguns. While this might seem obvious, the implications of this design affect everything from ammunition selection to shooting technique.

What this means practically:

• Pattern density becomes more important than individual projectile accuracy

• Range limitations are determined by pattern effectiveness, not ballistic capability

• Shot selection must match both game and shooting distance

• Choke selection becomes a critical performance factor

The Pattern Density Principle

The key is to make sure your pattern density is adequate for your intended use. You don't want dense spots or open gaps at the range you'll be shooting.

What I've learned about patterns:

• Consistent density matters more than tight groups

• Even distribution prevents gaps that game can slip through

• Center density should be strongest for vital zone hits

• Pattern size must match target size and range

Shot Selection: Balancing Size and Performance

The Physics of Shot Performance

Smaller shot provides better patterns but isn't effective for all game. Conversely, larger pellets equal more inertia, which equals more stopping power.

Understanding shot performance:

• #6 shot delivers approximately 1½ pounds of force at 40 yards

• Hit a bird with 6 pellets at that distance and you're delivering 7-8 pounds of force

• Multiple hits are what make shotguns effective, not individual pellet energy

• Shot size selection must balance pattern density with individual pellet effectiveness

Practical Shot Selection

What I've observed in the field:

• Smaller shot (7½, 8, 9) for clay targets and small birds

• Medium shot (4, 5, 6) for most upland game

• Larger shot (BB, 2, 4 Buck) for waterfowl and larger game

• Buckshot for deer and personal defense applications

Shotgun Patterning Guide: Why 40 Yard Testing Matters

Why Patterning Matters

You wouldn't take a rifle to the field without sighting it in and checking it, BUT people do this with shotguns all the time. This is one of the biggest mistakes I see hunters make.

The dangerous assumption: Many people think you can't miss with a shotgun. This couldn't be further from the truth.

Proper Patterning Procedure

40 yards is the average distance for hunting and patterning – this has become the standard for good reason.

What to check:

1. Point of Impact (POI): Where the pattern centers relative to your aim point

2. Pattern density: How evenly the shot is distributed

3. Pattern size: Overall spread at your intended shooting distance

4. Consistency: How repeatable your patterns are shot-to-shot

What good patterns look like: Best patterns are most dense in the center and evenly dispersed without significant gaps or overly dense areas.

Internal Ballistics: The Forcing Cone

Understanding the Forcing Cone

You want a long forcing cone – think of it as "the choke before the choke." This is an area where many factory shotguns can be improved.

Why forcing cones matter:

• Most factory guns have too steep of an angle in the forcing cone

• Elongating the forcing cone releases pressure more gradually

• Shot flies straighter and experiences less deformation

• Improved patterns and reduced felt recoil often result

The Technical Benefits

What I've learned about forcing cone work:

• Gradual transition from chamber to bore reduces shot deformation

• Lower pressure spikes mean less stress on the shot column

• Better patterns often result from this relatively simple modification

• Professional work is usually required for optimal results

Choke Systems: Your Pattern Control

Choke Fundamentals

Chokes are like tires: mass-produced with different types for different applications. Understanding this relationship helps in selection.

How chokes work:

• Located at the muzzle, chokes restrict shot into tighter groups

• Full choke is the tightest commonly available restriction

• Different constrictions produce different pattern sizes

• Choke selection should match your shooting application

Critical Installation Factors

The choke must be perfectly centered in the bore to optimize patterns. This is more critical than many people realize.

What can go wrong:

• Improper installation can easily put you 3-4 inches off at 40 yards

• Worn threads affect choke alignment

• Damaged choke tubes create inconsistent patterns

• Incorrect torque can affect performance and safety

Maintenance Considerations

Anti-seize compound is important for choke tube maintenance, especially with steel shot.

Why this matters:

• Steel shot doesn't compress like lead and beats up threads

• Steel shot can friction-weld choke tubes in place

• Regular maintenance prevents expensive extraction problems

• Proper lubrication extends choke tube life

Back-Boring: Advanced Performance Modification

Understanding Back-Boring

Back-boring is the process of enlarging the bore size slightly to improve performance.

How it works:

• Allows the wad to expand after leaving the chamber

• The choke then restricts the pattern to desired size

• Very popular with trap shooters for consistency

• Can improve patterns in many shotguns

When Back-Boring Helps

What I've observed:

• Older shotguns often benefit more than modern ones

• Tight-bored guns see the most improvement

• Competition shooters often pursue this modification

• Professional work is essential for proper results

Shotgun Fit: Critical for Performance

Why Fit Matters More with Shotguns

There's no rear sight on a shotgun – you point, not aim. This makes fit absolutely critical for consistent performance.

What proper fit accomplishes:

• Natural pointing without conscious adjustment

• Consistent sight picture every time you mount the gun

• Proper pattern placement relative to your point of aim

• Comfortable shooting without strain

Common Fit Problems

A lot of shotguns have too much pitch for the average shooter.

Signs of poor fit:

• If your pattern is dead-on where you aim, your fit is probably wrong

• Consistent high or low impacts indicate pitch problems

• Difficulty achieving consistent cheek weld

• Uncomfortable gun mount or awkward shooting position

Fit Guidelines

Better to be a little short than a little long when it comes to length of pull.

What to aim for:

• Your eye should be dead-on with the center of the rib

• Natural gun mount without strain or awkward positioning

• Consistent sight picture every time you shoulder the gun

• Comfortable shooting for extended periods

Barrel Length: Modern Reality vs. Old Beliefs

The Historical Context

You no longer need a long barrel for long-distance shooting. This is a holdover from black powder days.

Why long barrels were once necessary:

• Black powder needed time to burn completely

• Longer barrels allowed more complete combustion

• Velocity increased with longer barrels using black powder

• Modern smokeless powder burns much more efficiently

Modern Barrel Considerations

Short barrels can shoot just as far with proper setup using modern ammunition.

What determines performance now:

• Choke selection has more impact than barrel length

• Ammunition quality affects performance more than barrel length

• Proper gun fit matters more than a few inches of barrel

• Handling characteristics often favor shorter barrels

Practical considerations:

• Longer barrels provide longer sight radius and smoother swing

• Shorter barrels are more maneuverable in tight cover

• Balance point affects handling more than overall length

• Personal preference plays a significant role

Modern Developments Since 2019

Ammunition Improvements

Shot shell technology has continued advancing:

• Better wad designs for improved patterns

• Improved shot materials for better performance

• Specialized loads for specific applications

• More consistent manufacturing across all price ranges

Choke Technology

Choke tube design has evolved:

• Extended chokes for easier removal and better patterns

• Specialized constrictions for specific shot types

• Better materials for longer life and performance

• Ported chokes for recoil reduction

Gunsmithing Techniques

Performance modification methods have improved:

• Better forcing cone work with modern tools

• More precise back-boring techniques

• Improved stock fitting methods

• Better understanding of internal ballistics

Practical Application: Getting the Most from Your Shotgun

The Systematic Approach

Start with proper gun fit, then work on ammunition selection and patterning.

My recommended process:

1. Ensure proper gun fit first

2. Select appropriate ammunition for your application

3. Pattern test at your intended shooting distance

4. Adjust choke selection based on pattern results

5. Practice with your chosen setup until proficient

Common Mistakes to Avoid

What I see frequently:

• Assuming all shotguns shoot the same with the same ammunition

• Never patterning their gun and load combination

• Using inappropriate chokes for their shooting application

• Ignoring gun fit issues that affect performance

• Not maintaining choke tubes properly

Professional Services

When to seek professional help:

• Gun fit assessment and stock modification

• Forcing cone work for improved performance

• Back-boring for competition or specialized applications

• Pattern analysis and load development

• Choke tube installation and maintenance

Illinois-Specific Considerations

Hunting Regulations

With 70% of Illinois hunting done with shotguns, understanding performance is crucial for success.

What this means for Illinois hunters:

• Slug guns for deer hunting require different considerations

• Waterfowl hunting demands specific shot types and chokes

• Upland bird hunting benefits from proper gun fit and choke selection

• Turkey hunting requires specialized loads and tight chokes

Local Opportunities

Illinois offers excellent opportunities to put shotgun knowledge to use:

• Waterfowl hunting on Illinois rivers and lakes

• Upland bird hunting for pheasant and quail

• Turkey hunting in spring and fall seasons

• Clay target sports at local clubs and ranges

Final Thoughts

After years of working on shotguns and talking with hunters and shooters, I've learned that understanding how your shotgun actually works makes you a more effective and successful shooter. The mechanics aren't complicated, but they're often overlooked.

What continues to impress me is how much difference proper setup and understanding can make in shotgun performance. A properly fitted gun with the right choke and ammunition selection will consistently outperform an expensive gun that's poorly set up.

Key takeaways I keep coming back to:

• Pattern your gun with your chosen load and choke combination

• Gun fit is critical – more so than with rifles or handguns

• Choke selection should match your shooting application

• Maintenance matters – especially with choke tubes and steel shot

• Understanding the mechanics helps you make better equipment choices

For Illinois hunters: With shotguns being our primary hunting tool, taking time to understand and optimize your setup will pay dividends in the field.

No matter your era, we got your six – whether you're shooting a classic side-by-side or a modern semi-automatic, understanding the technical aspects will make you a better shotgun shooter.

Questions about shotgun performance, patterning, gun fit, or technical modifications? Blue Coat Arms Company provides comprehensive shotgun services including forcing cone work, stock fitting, and performance optimization. Contact us at 217-416-5962 or BlueCoatArms@gmail.com.