Quick Answer
Patterning a shotgun means firing at a large sheet of paper to see how your chosen cartridge and choke combination spreads its shot. Most UK shooters pattern at 40 yards using a 30-inch circle, counting pellet strikes to check the pattern is even, centred, and dense enough for the job in hand.
What Is Shotgun Patterning and Why Does It Matter?
Patterning tells you exactly where and how densely your shot lands on target, rather than relying on assumptions about your choke and cartridge combination.
Every shotgun, choke, and cartridge combination performs slightly differently. Two guns with the same nominal choke can throw noticeably different patterns depending on barrel manufacture, cartridge wad design, and shot size.
For clay shooters this affects hit consistency. For game and pest control shooters it directly affects clean, humane kills. A pattern that is too open at range risks wounding rather than dispatching quarry.
How Do You Set Up a Pattern Test?
A proper pattern test needs a large paper sheet, a fixed distance, and a consistent aiming point.
What You Need
- A sheet of paper at least 4 feet square (a patterning plate or builder's paper works well)
- A solid backing board or stand
- A measured distance, typically 40 yards for standard game loads
- A marker pen to mark your aiming point before firing
Step-by-Step Process
- Mark a clear aiming point (a cross or dot) on the paper
- Stand at your chosen distance, most commonly 40 yards
- Fire a single shot at the aiming mark, shooting from a rested or supported position for consistency
- Draw a 30-inch circle centred on the densest part of the pattern
- Count the pellet holes inside the circle
- Repeat 3-5 times per cartridge and choke combination to get a reliable average
What Distance Should You Pattern At?
40 yards is the standard distance used across most UK game and clay shooting patterning, as it reflects realistic range for driven game and many clay presentations.
Some disciplines warrant testing at other distances too. Pest controllers dealing with close-range rabbit or pigeon work may also pattern at 20-25 yards, since chokes behave differently at shorter ranges.
| Distance | Typical Use |
|---|---|
| 20-25 yards | Close pest control, decoying pigeon |
| 30 yards | General clay and game testing |
| 40 yards | Standard driven game benchmark |
| 50+ yards | Long-range wildfowling or specialist loads |
How Do You Read a Shotgun Pattern?
Once you have fired your test shot, count the pellet strikes within the 30-inch circle and compare this to the total pellet count in the cartridge.
Calculating Pattern Percentage
Divide the pellets counted inside the circle by the total pellets in the cartridge, then multiply by 100 to get a percentage. This tells you the choke's effective constriction at that distance.
| Choke Constriction | Approximate Pattern % at 40 Yards |
|---|---|
| Cylinder | 35-40% |
| Improved cylinder (quarter choke) | 45-50% |
| Half choke (modified) | 55-60% |
| Three-quarter choke | 65-70% |
| Full choke | 70%+ |
These figures vary by cartridge and manufacturer, which is exactly why patterning your own gun matters rather than relying on published averages.
What to Look for Beyond the Percentage
- Even distribution - avoid gaps large enough for a target or bird to pass through unhit
- Centring - the densest part of the pattern should align with your aiming point, not consistently off to one side
- Consistency across shots - fire multiple rounds to confirm the pattern is repeatable, not a one-off
Why Does Pattern Testing Differ From Cartridge to Cartridge?
Wad design, shot hardness, and pellet size all influence how tightly or loosely a cartridge patterns through the same choke.
Fibre wads generally produce slightly more open patterns than plastic cup wads, since they offer less protection to the shot as it travels down the barrel. Harder, nickel or copper-plated shot tends to deform less and pattern more consistently than soft lead alternatives.
This is why serious clay and game shots often test 2-3 cartridge brands through their preferred choke before settling on a combination for the season.
Do You Need Specialist Equipment to Pattern a Shotgun?
No specialist equipment is required. A patterning plate is convenient but not essential.
A large sheet of builder's paper, an old bedsheet marked with a grid, or purpose-made patterning targets from shooting suppliers all work equally well. What matters most is a consistent, measured distance and a stable shooting position so your results are comparable between tests.
How Often Should You Pattern Test Your Shotgun?
Most experienced shooters pattern test when they change cartridge brand, change choke, or at the start of a new season to confirm their setup is still performing as expected.
If you notice inconsistent results in the field, such as more pricked or wounded quarry than usual, this is a strong signal to re-pattern and check whether your choke and cartridge combination still suits the job.
Key Takeaways
- Pattern at 40 yards using a 30-inch circle for standard game and clay testing
- Fire multiple shots per combination to get a reliable average, not a single result
- Compare pellet count inside the circle against total pellets to calculate pattern percentage
- Cartridge choice affects pattern as much as choke selection
- Re-test whenever you change cartridge, choke, or notice inconsistent results in the field
Frequently Asked Questions
What distance should I pattern my shotgun at?
40 yards is the standard distance for testing game and general clay loads in the UK, as it reflects a realistic range for driven game shooting. Closer-range disciplines, such as pest control, may also benefit from testing at 20-25 yards.
What size circle should I use to measure a shotgun pattern?
A 30-inch circle is the standard measurement used to assess shotgun patterns. Draw the circle centred on the densest concentration of pellet strikes on your test sheet, then count the holes inside it.
How many pellets should hit inside the pattern circle?
This depends on your choke, cartridge, and shot size, ranging from around 35-40% of total pellets for cylinder choke up to 70%+ for full choke at 40 yards. Patterning your own gun and cartridge combination gives a more accurate figure than published averages.
Do I need a patterning plate to test my shotgun?
No. A large sheet of paper, at least 4 feet square, mounted on a stable board works just as well as a purpose-made patterning plate. Consistency of distance and aim matters more than the equipment used.
Why does my pattern look uneven or patchy?
Uneven patterns can result from a mismatched choke and cartridge combination, worn or damaged choke tubes, or inconsistent cartridge quality. Testing several cartridge brands through the same choke often resolves patchy results.
Should I pattern test a new shotgun before using it for game shooting?
Yes, patterning a new shotgun before the season starts confirms your choke and cartridge combination performs as expected, helping ensure clean, humane kills in the field rather than discovering issues on a live quarry.
Does choke constriction alone determine my pattern?
No. Cartridge wad type, shot hardness, and pellet size all significantly affect pattern density and spread alongside choke constriction. This is why two shooters with identical chokes can get different results depending on their cartridge choice.
How many test shots should I fire per cartridge and choke combination?
Fire at least 3-5 shots per combination to get a reliable average pattern. A single shot can be misleading due to normal shot-to-shot variation.