Shotgun Chokes Explained: Choke Chart & Patterning Guide

A choke changes pattern density, and pattern density is what sets your useful range. It does that by narrowing the bore over the last portion of the barrel so the shot column is squeezed before it leaves the muzzle. Tighter constriction keeps more pellets inside a given circle further out. Looser constriction spreads them sooner. That is the mechanism in shorthand, and makers tune taper and parallel-section geometry around it. Everything else on this page is about the fact that they measure and label the result differently.

Constriction is expressed in thousandths of an inch of bore reduction. Cylinder is nominally .000, Improved Cylinder .010, Modified .020, Full .035 under Briley's labels. Those numbers are a scale, not a specification you can carry across brands. Carlson's and Trulock publish .030 inch as Full, five thousandths more open than Briley at the same stamped name, and Browning states outright that its Invector-DS designations are based on delivered pattern rather than measured inside diameter alone. Two tubes stamped Full can be two different tubes.

The parallel section matters too. Behind the taper, a choke tube carries a straight length that the shot column travels through before it exits, and makers tune it. Carlson's builds its Gold Competition Target line with a parallel section 25 percent longer than its own standard flush tubes. That is a design difference inside one brand at the same nominal constriction, which is another reason a stamped label is a starting point and not an outcome.

None of this predicts what a specific shell will do. Browning publishes a patterning procedure precisely because you have to look at where the pattern lands and how dense it is inside a measured circle, with the gun, tube, and shell you actually own. A pattern percentage is an expected range for the test conditions the maker cites, not a guarantee for another shell, another bore, another distance, or another choke maker.

Here is the shotgun choke chart with its sources named. The nominal constriction column is Briley's 12-gauge labeling from its Understanding Chokes reference. The pattern columns are Browning's, and Browning scopes them tightly: the first is the expected percentage of the load inside a 30-inch circle at 40 yards from 12-gauge Standard Invector and Invector-Plus barrels using 2.75-inch lead loads in 3-inch chambers. The second column is Browning's separate Invector-DS dataset, which it does not publish for Cylinder or Extra Full.

Read the two pattern columns as two different measurements, not as a discrepancy. Browning built the Invector-DS numbers around delivered pattern, which is why Improved Cylinder shows a tight 40 to 45 percent band there and a wide 25 to 55 percent band in the older system. The wide bands are honest: the same tube throws different percentages with different shells.

Keep the source label visible whenever you quote a constriction. Full is .035 inch to Briley and .030 inch to Carlson's and Trulock, so a tube swap between brands at the same stamped name is a real change in constriction. Sources for this chart: Briley, Understanding Chokes and Browning, Shotgun Choke Patterns.

Constriction tells you what a tube does. The thread system tells you whether it will thread into your barrel at all, and the two are unrelated. Buying by shotgun model name is where people lose money, because several makers ship more than one system under one model family and at least one major maker sells three similar-sounding systems that do not interchange.

Even the makers disagree about where the lines sit, which is the strongest argument on this page for reading your own barrel. Mossberg's 12-gauge Accu-Choke page states its tubes interchange with Win-Choke and Browning Invector models. Winchester says Invector-Plus, WinChoke, and Standard Invector tubes are not interchangeable with one another. Both statements are official and they do not agree, so follow the maker of your barrel, not the maker of the tube you happen to be holding. Winchester's warning explicitly includes Invector-Plus, and Browning says an Invector-DS tube fits only barrels marked Invector-DS.

Beretta splits the same way. Mobilchoke tubes belong only in Mobilchoke barrels, and Beretta keeps original Optima-Choke, Optima-Choke Plus, and Optima-Choke HP separate from each other. Beretta limits HP tubes to barrels marked for Optima-Choke HP and warns that wrong-system use can damage the barrel, which is the sharpest version of why this section exists.

Benelli is the naming trap. Benelli's current M4 page calls the M4 tubes Standard, and Benelli's own catalog calls its other system Crio. The Crio Plus label you see on aftermarket tubes is a tube-maker label, and Benelli does not publish a Crio-to-Crio Plus interchange statement, so a Crio Plus tube is not automatically a Crio tube. Carlson's puts an even sharper warning on the pairing: Beretta Optima Plus and Benelli Crio Plus can share exterior dimensions while using different bores, and the same is true of Beretta Optima and Benelli Crio. Do not interchange either pair on the strength of how the tube looks.

Gauge is a hard gate on top of all of this. A system name shared between a 12-gauge and a .410 barrel is not a statement that the tubes cross, and Savage's 301 FAQ is a good example: the .410 models use a Short Invector pattern that its separate 12- and 20-gauge wording does not cover.

Here is where the shotguns in our catalog land. Every row is sourced to the firearm maker rather than to a choke-tube interchange chart, because the firearm maker is the one who knows what it cut into the barrel. If you are still choosing a gun, pump shotguns and tactical semi-autos split hard on this: some ship threaded, some ship fixed, and the spec sheet is worth reading before the tube catalog is.

Patterning is the step that turns a choke label into a number you can trust, and the procedure changes with the load. Three makers publish the four different procedures below, and the target size, round count, and scoring circle are not interchangeable between them. Run the one that matches what is in the gun.

Notice how far apart these are. Browning counts pellets inside a 30-inch circle on a 40- to 50-inch board at 40 yards across 3 to 4 targets. Trulock uses ten rounds of buckshot on paper at least three feet wide and scores a 20-inch circle. Federal works a turkey gun from 10 through 50 yards against a 10-inch circle, because the question there is the distance at which the pattern still puts enough pellets into a head and neck. Browning and Trulock both average repeated patterns rather than judging one shot, and that averaging is the part shooters skip.

There is no universal buckshot choke, and the two most-cited pieces of guidance point in different directions because they are answering different questions. Mossberg recommends Modified or Full for buckshot and still tells the owner to test the actual load. Federal LE says its tactical FLITECONTROL loads perform well from Cylinder-bore barrels and directs the shooter to select the choke that produces the desired pattern. Neither statement is a rule for the other maker's gun or the other maker's shell.

The wad generation is the detail that decides whether a ported tube is even in play. Federal says FLITECONTROL FLEX works through all waterfowl chokes, including ported tubes. Trulock says original FLITECONTROL should not be used with its ported tubes while FLEX may be used. Read the box, identify which wad you have, and keep the attribution attached, because the tube maker and the ammunition maker are each speaking about their own product.

Dedicated buckshot tubes are their own category with their own limits. Carlson's markets a Beretta and Benelli Mobil buckshot tube at a .695 product-specific exit diameter for 00 and 000 buckshot, and publishes its own shot-material, shot-size, and velocity limits for it. That is a tube-level specification, not a constriction class, which is why it does not appear on the chart above.

If your barrel is independently verified for Briley's Benelli Crio Plus pattern, the three Briley tubes above give you a clean constriction ladder to test with: Cylinder at .000 nominal, Improved Cylinder at .010, Light Modified at .015. Run the same shell through all three and let the paper rank them. That is a deliberate test sequence for a verified Crio Plus barrel, not a recommendation for any particular Benelli, because Benelli's own M2 literature says Crio rather than Crio Plus.

Score it Trulock's way: ten rounds, paper at least three feet wide, a 20-inch circle, and an average rather than a verdict from one lucky target. Ten rounds of buck is the price of knowing. For the guns this testing usually happens on, see our home defense shotgun guide, and for the short, weather-beaten pump that lives behind a seat, the truck gun guide covers the same trade in a different package.

Turkey chokes are the tightest constrictions most shooters will ever thread in, and tungsten super shot is where the usual shortcuts break down hardest. Federal says its HEAVYWEIGHT TSS load with the FLITECONTROL FLEX wad works through standard and ported turkey chokes, and it deliberately does not prescribe one universal constriction. That is the ceiling of what the shell maker will tell you: the rest comes from the tube maker and from your own pattern board.

Tube-specific limits are strict and worth reading in full. Carlson's optimizes its .640 Rem Choke TSS tube for Federal HEAVYWEIGHT TSS in #7 through #9, and prohibits steel larger than #4, slugs, sabots, rifled slugs, and 00 or 000 buckshot through that tube. Those are the tube maker's own restrictions for its own product, and they do not transfer to the next brand of turkey choke.

Indian Creek publishes a fitment table organized by choke family and sells separate model numbers and constrictions inside it, so the family name is never the order. Indian Creek allows lead and hybrid heavy loads in shot sizes #2 through #10, and on TSS specifically it tells you to consult the shell manufacturer. Pick the exact host variant and constriction off its table, then pattern it.

Do not carry steel-shot restrictions over to TSS by analogy. They are different materials with different hardness and different maker guidance, and the only correct move is to use the exact shell maker and choke maker statements for the two products you are actually combining.

Then pattern it Federal's way: test the exact gun and choke from 10 through 50 yards and compare hits inside a 10-inch circle, which gives you a practical distance derived from your pattern instead of from a marketing claim. If you are still building the gun around that tube, our turkey shotgun guide covers the platforms whose factory choke systems feed this decision.

For clays, two makers publish starting choices and they do not agree, which is fine as long as you do not blend them. Browning's game-selection chart gives Full, Improved Modified, or Modified for trap and Skeet for skeet. Beretta publishes Cylinder or Improved Cylinder for skeet and Modified or Improved Modified for trap. Pick one maker's starting point, shoot it, and let the board decide, rather than averaging the two into a chart neither of them published.

Steel is where a wrong assumption gets expensive, and every rule worth having is attached to a name. Beretta marks Cylinder, Improved Cylinder, and Modified Mobilchoke constrictions steel-compatible in the A300 manual and does not recommend Full or Improved Modified for steel there. Benelli recommends no tighter than Modified with steel, with Modified for pass shooting and Improved Cylinder or Cylinder over decoys. Winchester generally says no tighter than Modified unless the exact tube is marked for tighter steel use.

Browning accepts current factory steel loads in current Standard Invector, Invector-Plus, and Invector-DS systems, does not recommend Standard Invector Full or Extra Full with steel, and publishes exclusions for older guns. Mossberg allows steel with the proper Accu-Choke or Accu-Mag steel-rated tube and does not recommend steel through its Extra-Full turkey tube. Five makers, five separate statements, and no universal answer about Full and steel.

Aftermarket tubes publish their own material ratings on top of the gun maker's. Carlson's rates its Gold Competition Target line for lead, copper-plated, nickel, Hevi-Shot, bismuth, and tungsten loads, and its steel guidance is product-specific: the restriction on steel larger than BB applies to tubes tighter than Full. The two Carlson's Improved Cylinder tubes above, one cut for Rem Choke and one for Invector-Plus, are the clays and pattern-comparison end of that line, with listed exit diameters of .720 inch and .730 inch respectively.

Verify all of it on paper with Browning's general procedure: a 40- to 50-inch board at 40 yards or at the distance you actually shoot, 3 to 4 fresh targets, a 30-inch circle around the densest portion, hits divided by the shell's pellet count, and the targets averaged.

Slugs are the clearest case where two manufacturers publish conflicting boundaries, so the answer has to be your gun's maker. Benelli recommends Cylinder, limits rifled slugs in its smoothbore field barrels to Cylinder or Improved Cylinder, calls anything tighter than Improved Cylinder unsafe, and reserves sabot slugs for fully rifled barrels. Remington says rifled slugs or buckshot may be used through any smoothbore choke and generally identifies Improved Cylinder as best. Both statements are correct about the guns their authors built. Neither is a universal rule, and running a Benelli on Remington's wording is exactly the mistake this section exists to prevent.

Mossberg lands near Remington in practice with a hard exception: Improved Cylinder for slugs, and 835 or 935 overbored vent-rib barrels require a dedicated slug barrel rather than a tube change. Winchester identifies Cylinder and Improved Cylinder WinChokes for rifled and sabot-type slugs in guns covered by its Model 1300 manual, and requires that a tube stay installed in a choke-threaded barrel at all times.

Dedicated rifled choke tubes are a separate product class with their own permissions. Carlson's permits slugs, rifled slugs, and sabots through its rifled choke tubes while prohibiting all of them through its turkey tubes. Those two lines come from the same maker and say opposite things, which is the cleanest illustration on this page that a limit belongs to a specific tube rather than to a constriction class.

Slug work is sighted in rather than patterned. Federal's method is to sight in from a rest that reproduces the support and fore-end pressure you will actually use, then verify point of impact from alternate support positions, because the support method moves impact. Photograph the group and measure the point-of-impact shift between positions instead of eyeballing it. A dot makes that shift easier to see and easier to correct, which our shotgun red dot guide covers in detail.

The SilencerCo Salvo 12 mounts through the choke interface using an Echo Choke Mount rather than through a threaded muzzle, so it attaches using the same thread system this guide has been mapping. That makes your choke system a suppressor decision as well as a pattern decision, and it is one more reason to confirm the marking on the barrel rather than the model name on the receiver. Our shotgun suppressor guide covers which cans mount to which systems.