Choke Tube Identification

WHAT IS THE CORRECT CHOKE TUBE SYSTEM FOR MY BROWNING SHOTGUN?

It is very important to understand that there are three different choke tube systems from Browning that have been produced over the years. They are not interchangeable. In addition, the same shotgun models have been fitted with different choke tube systems over the years. Each system is found on various models of current Browning shotguns. Confusing? Carefully read below and you will not make a mistake when ordering choke tubes for your Browning. 

Invector-DS Choke Tubes. The newest and most advanced Browning choke tubes. However:

  • Invector-DS choke tubes only fit Browning shotguns with Invector-DS marked on the barrel(s).
  • They are much longer than other Browning choke tubes and have threads on the muzzle end of the tube.
  • DO NOT buy these if you have a shotgun marked Invector Plus (+) or Standard Invector.

These new choke constriction technologies found on Invector-DS choke tubes improve pattern performance beyond what was previously thought possible.

Invector DS Choke Tubes

Look for a barrel stamp that says "Invector DS" like the one pictured above.

Invector-Plus Choke Tubes. Barrels marked Invector Plus ( or Invector+) will not accept "DS" or "Standard" Invector.

  • These choke tubes only fit Browning shotguns with Invector Plus (+) on the barrel (s).
  • They are found on 12 and 20 gauge Browning shotguns and have been a mainstay of Browning performance for over 20 years.
  • Multi-gauge sets found on Citori over and unders, will often have a mix of Invector Plus (12 and 20 ga.) and Standard Invector (16 ga., 28 ga. and .410 bore).

Invector Plus features a longer design for improved pattern performance. Considered a significant breakthrough in choke tube design. 

Invector Plus Choke Tubes

Look for a barrel stamp that says "Invector Plus" like the one pictured above.

Standard Invector Choke Tubes. The original Browning removable choke tube system.  

  • These fit only shotguns marked Invector or Standard Invector.
  • They never fit shotguns marked Invector Plus (+) or Invector-DS.
  • 10 ga., 28 ga. and .410 bore Browning shotguns always utilize the Standard Invector system. 
  • Most 16 gauges use the Standard Invector system, with the exception of the current A5 Sweet 16, which uses the Invector-DS system. 

Over the past 30 years, many products have featured the Standard Invector System. Extended versions are available for Standard Invector, which make them appear to be similar to the Invector Plus, but they are NOT interchangeable. 

Standard Invector Choke Tubes

Look for a barrel stamp that says "Standard Invector" or often simply "Invector" as pictured above.

BEFORE PURCHASING CHOKE TUBES . . . If you have any question at all regarding which tube fits your shotgun, be sure to call our customer service department during business hours, 8:00 AM to 4:30 PM Mountain time.  TOLL FREE: 1-800-333-3288

In all cases, the type of choke your barrel has is indicated on the barrel and for new shotguns can be found under the "Features" listing on the Browning website. 

What choke designs/systems are available in each gauge?

10 gauge

Made in one type of Browning choke. 

  • Standard Invector

12 gauge

 Made in three different chokes. 

  • Standard Invector
  • Invector Plus (or called Invector+)
  • Invector-DS

They are NOT interchangeable.

16 gauge 

Made in two types of choke tube. 

  • Standard Invector
  • Invector-DS (Current A5 Sweet 16)

They are NOT interchangeable.

20 gauge

Made in three different chokes tubes. 

  • Standard Invector
  • Invector Plus (Invector+)
  • Invector-DS

They are NOT interchangeable.

28 gauge 

Made in one type of choke.

  • Standard Invector

.410 bore 

Made in one type of choke tube.

  • Standard Invector (or called just "Invector")

UNDERSTANDING THE HISTORY OF BROWNING'S CHOKE SYSTEMS.

Chokes are an integral part of a modern shotgun. So when researching a Browning Citori or Citori 725 on the Browning website it is generally a good idea to confirm the type of choke each model is fitted with. Do this by looking on the barrel, on the choke or on our site by clicking on the model and looking under "Features." 

This is a good start. But due to the fact that some models have multiple barrels of multiple gauges, it can become much more confusing. But this is not a bad thing. The confusion is due to the very nature of multi-barrel sets and due to the act of producing sub-gauge models in versions based on 12 gauge models. Given that many of us love multi-gauge sets and sub-gauge over and unders, understanding the process is worth the time and effort. 

The special issue of multi-barrel set shotguns. An important fact is that mult-gauge/barrel sets are like the custom cars of the firearms business. They are not a run-of-the-mill product that is mass produced by the millions. A bit of customization is exactly what most customers want. The act of fitting all barrels makes them very close to "custom." Therefore it should be expected that a higher level of uniqueness will exist in what you purchase and that you will get a higher level of customization for your money. In other words, at this level of product, it pays to expect some "uniqueness" and expect to spend some extra time learning about the shotgun before you purchase. (And we believe the information below can help.)

If you are new to shotgunning, and in particular Browning shotgunning, it is important to know that none of the choke tube systems produced by Browning are interchangeable. They all have their own histories in the timeline of Browning's new features development over the years and they all fit a specific purpose. And all designs are still relevant AND EFFECTIVE today.  

Browning has produced three different basic choke tube designs since the end of the fixed choke era:

  • Standard Invector (sometimes called simply Invector)
    • A very early introduction in the marketplace, featuring a flush fit in the original configuration.
  • Invector Plus (sometimes Invector+)
    • A longer tube with improved pattern performance.
  • Invector-DS
    • A totally new concept in pattern performance and a breakthrough in creating a better tube to barrel seal.

All are currently available in extended versions which protrude beyond the end the the muzzle when screwed tightly in place. This means that determining the type of Browning choke system by length is not possible, or at best totally confusing. Refer to the inscription on the tube and match it up to the inscription on the barrel. That always works.

There are choke tubes within each of the three types desiged for specific purposes (such as steel shot or turkey hunting). For VERY detailed information on different types of Browning choke tubes avialable click here.

MULTI-GAUGE SETS.

Multi-gauge sets (shotguns with matched sets of barrels with different gauges). Browning makes over and under shotguns with multiple barrel sets fitted to a single receiver. These points below are essential for you to choose the correct accessory tubes for a multi-barrel set. 

  • In all cases, the 16, 28 and .410 barrels in multi-gauge sets will be STANDARD INVECTOR -- this means for all current Browning shotguns.
  • Generally, 12 and 20 gauge barrels in Citori 725 sets will be Invector-DS.
  • Generally, current 12 and 20 gauge barrels in Citori (non-725) sets will be Invector Plus.
  • Many older sets might be Standard Invector (beginning way back the 1980s) -- but no current sets.
  • There are no 10 gauge barrels in multi-barrel sets. 
  • For special builds and other specials, there may be exceptions. Always check the barrel first to know for sure before purchasing. 
  • The variations may seem confusing, but these sets are built in response to customer requests over time and will not always be consistent. That is not a problem if you will always check the barrels first to make sure you are happy with the choke type for each barrel or barrel set. 

The choke types of the 12 and 20 gauge models (and in fact all models) will be identified:

  • On the barrel
  • On the "Features" listing on the Browning website (when not listed, please call)
  • In the Browning printed catalog

ALWAYS DOUBLE CHECK.

Errors in online and printed literature. Due to the sheer volume of information found in Browning printed and digital literature it is possible that errors in specifications will occur. Occasionally an error in clarity in our printed or online information will occur. Sometimes a product change is simply missed in the effort to get the new information to you, our customers. Since many multi-barrel sets are "specials" made virtually "to order" the actual specifications for the model may not be known until well after the model is announced. Such is the lot of "nearly custom" products. We always regret human error, but it happens. Before making an expensive purchase of multi-barrel sets, or if you have any questions at all about the choke tube type your shotgun is fitted to accept, call our customer service department for clarification.

Browning Customer Service
One Browning Place
Morgan, UT 84050
TOLL-FREE:    1-800-333-3288

If you have any additional insights or desire clarification for any of the above we welcome your input. 

HOW TO IDENTIFY A CHOKE'S CONSTRICTION OR PATTERN RATING.

Browning choke tubes use several systems for identification. Some are useful in the field, and others when the choke tube is out. Choke tubes supplied with your Browning shotgun often have notches in the top edge which can help you determine the choke constriction. Generally you will need to remove it an read the inscription on the side of the tube. Below are a few helps:

GENERAL ABBREVIATIONS

(as found on product listings)

DESCRIPTIONS

XF

Extra Full

XF TRAP or X-FULL TRAP  

Extra Full Trap Shooting Choke

X FULL TKY-TRAP

Dual use extra full tube for turkey or trap shooting

X FULL TKY

Extra Full Turkey Hunting Choke

F

Full

LF or LFULL

Light Full

IMOD or IM or IMP MOD or I MOD

Improved Modified

MOD or M

Modified

LMOD or LM  or LT MOD or L MOD

Light Modified

IMP CYL or IC  

Improved Cylinder

SK or EXT SKT

Skeet

CYL or C

Cylinder (sometimes incorrectly abbreviated to CLY)

SPREADER

Special tube with a form of "rifling" that spreads the pattern rapidly, for close in upland hunting

RIF DEER

Rifled Deer Tube (for shooting slugs, primarily sabots)

 

 

NOTCHES IN RIM OF TUBE 

(OEM Invector and Invector Plus, not found on extended tubes)

I

Full lead or steel, but may be too tight for good steel performance

II

Modified lead, Improved Modifed Steel

III

Improved Cylinder lead, Improved Cylinder Steel

IIII

Skeet lead, Modifed Steel

NONE, no notch

Cylinder lead, Improved Cylinder Steel

 

 

SPECIALTY DESIGNATIONS

 

LONG

Tight constriction tube used for longer ranges, mostly referring to steel shot

MED

Medium constriction for medium ranges with steel shot

CLOSE or CLOSE RANGE

Very open choke tube used for close range shooting with steel shot. 

 

 

OTHER ABBREVIATIONS

 

WF

Waterfowl

TKY

Turkey

INV PLUS

Invector Plus choke tubes

INV

Invector Tubes (Standard Invector)

EXT

Extended choke tube that extends beyond the muzzle

INV DS

Invector-DS Choke Tube System

TNT

Timber and Teal (helically spun to spin shot)

AVERAGE PATTERN PERCENTAGES

Number of pellets in a 30" circle at 30 yards. Varies with shot size and/or lead vs. steel shot. Steel patterns generally exhibit a higher percentabe in the circle.  IMPORTANT: The following values are approximate. They do vary between gauges and the type, lenght and design of the choke tube. 

12 GAUGE

75%-85% -- Extra Full Trap

55%-85% -- Full 

30%-60% -- Light Modified

45%-75% -- Improved Modified

35%-65% -- Modified

30%-60% -- Light Modified

25%-55% -- Improved Cylinder

20%-45% -- Skeet 

15%-45% -- Cylinder

Very open -- Spreader

 

20 GAUGE 

55%-85% -- Full     

45%-75% -- Improved Modified   I

35%-65% -- Modified

30%-60% -- Light Modified  

25%-55% -- Improved Cylinder

20%-45% -- Skeet 

The Listing is the Exact Listing of Abbreviations and Choke Constrictions for Browning Invector-DS Tubes.

INVECTOR-DS CHOKE, 12, FULL 75-80%
INVECTOR-DS CHOKE, 12, LIGHT FULL 70-75%
INVECTOR-DS CHOKE, 12, IMOD 65-75%
INVECTOR-DS CHOKE, 12, MOD 55-65%
INVECTOR-DS CHOKE, 12, LMOD 45-55%
INVECTOR-DS CHOKE, 12, IC 40-45%
INVECTOR-DS CHOKE, 12, SK 35-40%

INVECTOR-DS CHOKE, 12, FULL, EXTENDED 75-80%
INVECTOR-DS CHOKE, 12, LIGHT FULL, EXTENDED 70-75%
INVECTOR-DS CHOKE, 12, IMOD, EXTENDED 65-75%
INVECTOR-DS CHOKE, 12, MOD, EXTENDED 55-65%
INVECTOR-DS CHOKE, 12, LMOD, EXTENDED 45-55%
INVECTOR-DS CHOKE, 12, IC, EXTENDED 40-45%
INVECTOR-DS CHOKE, 12, SK, EXTENDED 35-40%