With the exclusive Double Seal design.

The Browning Invector-DS choke tube system is the biggest leap forward in design since interchangeable choke tubes were introduced. With the Invector-DS, we’ve really done our homework and taken the proven thin wall, muzzle thread choke concept to the next level of shot

pattern performance. The exclusive brass alloy band at the base of the tube seals out gas and grit that sneaks between the barrel and tube, making the Invector-DS tubes easy to remove even after extensive shooting. Thin wall construction reduces the flare at the end of the barrel for a sleeker shotgun appearance. Lastly, the Invector-DS offers the most consistent, reliable tightening of any system ever. With all these features, you can’t lose with Invector-DS.

(Available only on the Citori 725 and upcoming Browning A5.)

THE SHOT PATTERN YOU WANT

When you thread in a choke tube, you expect it to give you the shot pattern you need for the shooting situation at hand. Invector-DS does this better than any of the competition's choke systems. From full to cylinder, the internal geometries of Invector-DS choke tubes have been tested again and again to ensure that patterns tighten consistently and reliably. With Invector-DS, you get even shot spacing between chokes when it comes to pattern percentages, and the pattern you want when you take the shot.

The top series of cone-shaped shot dispersion patterns illustrate the problem with many competitor's choke tube constriction configurations and designs. You can see how the Competitor's choke tubes show little pattern difference between the different choke constriction designations.

In the illustration, you can see how Browning's Invector-DS choke system scales the actual patterns to you get an even progression from the most open tubes to the tightest tubes.

Important: Browning Invector-DS choke tube designations are not based on the inside diameter as measured by a micrometer but by the actual pattern that is created by each choke.

In general practice patterns are determined by shooting at a 30" circle at 40 yards. Our goal in scaling the tubes is a consistent percentage of the pattern from full choke to cylinder choke. For example, a common specification for FULL CHOKE is for 65-75% of the total pellets to be in the 30" circle at 40 yards. IMPROVED MODIFIED would put 55-65% of the pellets in the circle at 40 years. MODIFIED would be about 45-55% and so forth. With today's Invector-DS tubes, constriction diameter is NOT the best way to determine choke performance. In fact, the same is true of many high-performance tubes.

INVECTOR-DS CHOKE TUBES ARE NOT LIKE ANY OTHER

The tubes fit flush with the end of the barrel but are longer than competitors’ tubes. Extended tubes (available as accessory) are even longer.

Proprietary differential banded gas seal eliminates residue build up and makes chokes easy to remove and install  Integrated spring suspension holds the seal tight, yet allows expansion against the barrel wall for a perfect fit and a smooth transition for shot column entering choke

    Gas is controlled at the interface between choke and where it seats in the bore

    From skeet to full choke, patterns tighten consistently and reliability.

THE ADVANTAGES OF THE EXCLUSIVE BROWNING INVECTOR-DS GAS SEAL

Invector-DS choke tubes feature a proprietary brass seal that prevents gas and grit from

slipping between the barrel and choke tube. This durable, long lasting seal compresses tightly against the barrel wall, eliminating residue build up on the choke tube threads and making installation and removal easier than any other choke system with muzzle threads.

Keeps threads clean so tubes don't gum up and become difficult to remove

Differential seal applies just enough friction around the perimeter to prevent the tube from working loose with shooting so you spend little to no time re-tightening tubes as you shoot.

After extensive shooting, competitors' choke tubes without a gas seal show significant grit and residue build up on the tube. The innovative gas seal on Browning Invector-DS tubes keeps the choke tube cleaner, for easier removal and installation.

TAKE A CLOSE LOOK AT THE SEAL AND HOW IT STOPS GAS LEAKAGE ON THE OUTSIDE OF THE TUBE.

    Area between tube and barrel stays clean

    The gas is blocked where the tube meets the shoulder in the bore and at the Differential gas seal around the circumference of the tube

    Gas exits completely through tube on the inside of the tube, not along the sides of the tube

    How does the Differential gas seal work? The special brass seal has multiple expansion cuts that allow it to compress snugly against the barrel wall and completely seal against gas leakage.

LONGER TUBE OVERALL LENGTH IMPROVES CHOKE TAPER

Longer overall length, as much as 1 1⁄8" longer than a leading competitor, allows a more gradual choke taper for denser shot patterns, better pattern percentages, and faster shot velocities. Longer extended Invector-DS magnify this advantage (available separately).

The competitors tube is shown at the top while the improved taper configuration of the Browning Invector-DS system is shown below.

EXTENDED INVECTOR-DS CHOKE TUBES

    Extends beyond end of barrel for easy removal and even tighter patterns

    Proprietary differential banded gas seal eliminates residue build up and makes chokes easy to remove and install

    Integrated spring suspension holds the seal tight, yet allows expansion against the barrel wall for a perfect fit and a smooth transition for shot column entering choke Gas is controlled at the interface between choke and where it seats in the bore From skeet to full choke, patterns tighten consistently and reliably

 EASIER TO INSERT AND REMOVE BY DESIGN

Clearly by having less residue buildup in the threads tubes will remove easier. And the Differential Seal will hold tubes in place shot after shot. It takes little if any effort to break a tube loose and spin it out -- a real advantage on the range. But you won't spend all day retightening tubes that have come loose due to an inferior design.