Choke Tube Diameter and Constriction Table

↬ Knowing the inner diameter of a choke tube is important to identify choke tube constriction. Chokes with tight diameters produce more compact patterns, while open chokes with less restriction produce wide patterns.

Jump to: Diameter Chart – Choke Sizes – Choke Markings – Recommendations

This chart lists choke sizes by both their measurements (to a thousandth of an inch) and by an alpha code naming system. Choke measurements range from open chokes of around 0.735″ to 0.770″, to more restrictive chokes of around 0.600″ to .0680″. Choke tubes sizes use a naming structure that translates to: (from open to tight) cylinder, skeet, improved skeet, improved cylinder, light modified, modified, improved modified, light full, full, extra full, and turkey.

Choke Tube Constriction Chart

Type	Gauge	Cylinder	Skeet	IS	IC	LM	M	IM	LF	Full	XF	Turkey
10 ga. Standard	10	0.775	−	−	0.768	−	0.758	−	−	0.740	−	0.730
12 ga. Fixed	12	0.729	0.719	−	0.716	−	0.705	0.695	−	0.685	−	−
Beretta / Benelli Mobil	12	0.726	0.721	0.716	0.711	0.706	0.701	0.696	0.691	0.686	0.681	−
Beretta Optima	12	0.732	0.727	0.722	0.717	0.712	0.707	0.702	0.697	0.692	0.687	−
Beretta Optima Plus	12	0.732	0.727	0.722	0.717	0.712	0.707	0.702	0.697	0.692	0.687	−
Beretta Optima HP	12	0.733	0.728	0.725	0.723	0.718	0.713	0.708	0.703	0.693	0.688	−
Benelli Crio	12	0.727	0.722	0.717	0.712	0.707	0.702	0.697	0.692	0.687	0.682	−
Benelli Super Sport	12	0.727	0.722	0.717	0.712	0.707	0.702	0.697	0.692	0.687	0.682	−
Bettinsoli	12	0.729	0.724	0.719	0.714	0.709	0.704	0.699	0.694	0.689	0.684	−
Blaser	12	0.732	0.727	0.722	0.717	0.712	0.707	0.702	0.697	0.692	0.687	−
Standard Invector	12	0.727	0.722	0.717	0.712	0.707	0.702	0.697	0.692	0.687	0.682	0.670
Browning Invector Plus	12	0.740	0.735	0.733	0.730	0.725	0.720	0.715	0.713	0.710	0.700	0.680
Browning Invector DS	12	0.740	0.735	0.733	0.730	0.725	0.720	0.715	0.713	0.710	0.700	−
Krieghoff	12	0.733	0.728	0.723	0.718	0.713	0.708	0.703	0.698	0.693	0.688	−
Lanber	12	0.727	0.722	0.717	0.712	0.707	0.702	0.697	0.692	0.687	0.682	−
Remington	12	0.727	0.722	0.717	0.712	0.707	0.702	0.697	0.692	0.687	0.682	−
Retay	12	0.725	0.720	0.717	0.715	0.710	0.705	0.700	0.698	0.695	0.680	−
Mossberg 835/935	12	0.774	0.767	0.764	0.760	0.752	0.743	0.735	0.730	0.727	0.710	0.680
Winchester/Moss. Invector	12	0.730	0.725	0.723	0.720	0.715	0.710	0.705	0.703	0.700	0.690	−
SKB	12	0.735	0.730	0.725	0.720	0.715	0.710	0.705	0.700	0.695	0.690	−
Beretta / Benelli Mobil	20	0.627	0.623	0.620	0.616	0.613	0.609	0.606	0.602	0.599	0.595	−
Browning Invector	20	0.618	0.614	0.611	0.607	0.604	0.600	0.597	0.593	0.590	0.586	−
Invector Plus	20	0.630	0.626	0.623	0.619	0.616	0.612	0.609	0.605	0.602	0.598	−
16 ga. Fixed	16	0.673	0.665	−	0.661	−	0.657	−	−	0.624	−	−
20 ga. Fixed	20	0.625	0.621	−	0.603	−	0.595	0.590	−	0.585	−	−
28 ga. Fixed	28	0.551	0.551	−	0.543	−	0.539	−	−	0.527	−	−
.410 Fixed	.410	0.409	0.404	−	0.404	−	0.402	−	−	0.398	−	−

The diameter table above shows the diameters and constrictions you can expect for choke tubes and shotgun barrels of a specific make and type, as well as 12-gauge choke sizes in inches, 10-gauge, 20-gauge, 16-gauge, 28-gauge, and .410 shotguns. The most popular choke systems are shown, which include Standard Invector, Invector Plus, Remington, Winchester Invector, and Benelli/Beretta Mobil. If you’re unsure about choke compatibility, consult the choke interchange lookup.

Related Products

Patternmaster Code Black Choke

Real Avid FINI Choke Wrench

Birchwood Casey 12in x 18in Target

Choke Tube Sizes

Choke tubes come in a wide range of sizes that can be used for many different hunting applications. Open chokes are best for fast flushing upland game birds and decoying waterfowl, while tight chokes provide the best results for turkey, long range waterfowl, and coyotes.

11 COMMON CHOKE SIZES

Cylinder
Skeet
Improved skeet
Improved cylinder
Light modified
Modified
Improved modified
Light full
Full
Extra full
Turkey

Cylinder is the most open choke available and is comparable to a straight bore. Turkey is the tightest choke tube, and it’s tighter than a full choke.

Choke Tube Markings

Markings on shotgun choke tubes come in a wide range of variations, but their meaning across the spectrum is largely the same. Manufacturers can use a notching/serration system, color coded, alpha naming scheme, and color banding to indicate the diameter of the choke tube. This is done for quick verification without having to remove the choke from the gun in most cases.

Browning Choke Tube Markings

Browning marks their choke tubes with the following numbers ranging from I to IIII. The I designation is a full lead choke and a IIII is for skeet lead.

I – Full Lead or Steel

II – Modified Lead, Improved Modified Steel

III – Improved Cylinder Lead, Modified Steel

IIII – Skeet Lead, Light Modified Steel

None – Cylinder Lead, Improved Cylinder Steel

Benelli Choke Tube Markings

Benelli marks their choke tubes with the following numbers ranging from I to V. The I designation is a full lead choke and a V is for cylinder.

I – Full

II – Improved Modified

III – Modified

IIII – Improved Cylinder

V – Cylinder

Beretta Choke Tube Markings

Beretta marks their choke tubes with the following numbers ranging from I to V. The I designation is a full lead choke and a V is for cylinder.

I – Full

II – Improved Modified

III – Modified

IIII – Improved Cylinder

V – Cylinder

For choke tubes with color banding, see the Choke Tube Color Chart Reference Guide to find the correct size.

Choke Identification Guides

Use these guides to help tell the difference between similar choke systems.

How Are Choke Tubes Measured?

Choke tube diameter is measured from the inside walls of the choke and recorded to a thousandth of an inch. This measurement determines the choke tube size. Choke tube markings are an easy way to visually confirm choke tube diameter without having to measure.

The easiest way to identify the size of a choke tube is to look for writing etched into the outer walls of the choke. Chokes are often labeled with the choke size in the center area running parallel with the threads and end of the tube.

If a choke tube has no markings, then a bore gauge tool or calipers capable of measuring to a thousandth of an inch is the only accurate way to get a measurement. Place the calipers even with the inner wall of the choke tube and then compare the result to the choke tube chart above to determine its size.

What Size Shotgun Choke Should You Use?

If you’re feeling overwhelmed by the amount of choke sizes to choose from (there are at least 11 after all), you aren’t alone. Choosing the right choke size should be based on what game you will be hunting, the distance you expect to shoot, and the shot size.

Game Animals

Naturally the choke you use for dove hunting will not be the best for long range pass shooting on geese. Factoring in the game you will be hunting is the first step to choosing the right choke tube.

Upland and fast-moving small birds require open chokes like skeet and improved cylinder. Duck hunting over decoys requires a modified or light modified choke. Turkey hunting and long-range passing shots on geese work best with full and extra full choke tubes.

See this guide for more on selecting the right choke tube based on the effective ranges for waterfowl.

Distance

The second factor to consider when choosing a choke size is the average distance most game will be at when you pull the trigger. Open chokes such as cylinder and light modified will help shotgun patterns expand quicker (between 20 and 30 yards) once it leaves the barrel. This isn’t ideal for keeping tight patterns at longer ranges but is perfect for flushing quail and pheasants.

Tighter chokes like full and turkey are designed for shots over 50 yards and would not be ideal for dove hunting. These tight chokes keep the pellet distribution too compact to hit fast moving close in shots on small birds.

See this guide for more info on determining the effective range of TSS for turkeys.

Shot Size

The last factor to consider when selecting a choke size is the pellet diameter. Pellet sizes range from small #8 to large T shot steel and even buckshot. Smaller shot, such as #7.5, is best for short range shots on small game like dove within 35 yards and may only require an improved cylinder choke.

Large pellets such as BBB steel are best for shots on geese up to 50 yards and work best through modified or improved modified chokes. Buckshot for coyote hunting may only require a modified choke to be effective past 60 yards.

For more on selecting the right pellet size and shot type, see the pellet size chart here.

RELATED – Looking for a NEW choke tube? See the TOP PICKS here!

Conclusion

The choke tube chart shown at the beginning of this article is the best starting point when identifying choke tube size. Choke diameter measurements can differ by both brand and gauge. It’s important to identify the choke size you will be shooting so that you can determine it’s compatibility and how it will perform during certain hunting situations.

When selecting the size of choke needed, always consider the average distance the shots will be on the game being hunted. Small shot sizes on fast moving birds require open chokes like cylinder and improved cylinder, while long range hunting work best with tight chokes like improved modified and full choke.

Was this helpful?

Search Chokes by Gauge

Related

Latest Posts