November 03, 2010
Waterfowlers wonder which choke tubes are safe to use with the tungsten-based pellets in today's factory loads. To find out, I set up a hands-on, real-time test including several different types of chokes matched to different types of tungsten shot.
Modern choke tubes are more than capable of taming tungsten loads.
In general, tungsten and its density -- regardless of pellet size -- won't require as much choke constriction to obtain quality pattern at average shooting ranges (35 to 45 yards). A 30-inch circle can be filled out nicely with a modified choke. But when payloads driven through a factory modified choke push past 45 yards, patterns are less reliable. Even a tightly constricted turkey choke can leave a messy pattern by the 47-yard marker. What takes place is debatable, but for the most part, the core pattern (inner 20-inch circle) becomes quite thin. As a result, not many pellets are left to fill out the longer-range pattern, which has become stressed by extended range.
For choking waterfowl shotguns, the basic program of turkey hunters and ultra-tight chokes goes out the door -- duck and goose hunters need a more open pattern. Shooting grapefruit-size balls of shot at 50 yards is not the ideal duck hunter's payload control.
Hunters want extended range, and Hevi-Shot, Winchester Xtended, Remington HD or other variations of tungsten deliver raw energy at extreme distances. Uniform 30-inch patterns near 100 percent at 40 yards are the goal for an effective waterfowl load.
My testing was conducted with a Winchester Super X3 and a Remington 870 Express chambering two different chokes. I used pattern boards for percentage of on-target evaluation. All testing was done at 40 yards -- the standard pattern test and review range used by the shooting industry. See the table for the results.
Without question, these results will not occur with standard steel shot at the frequency illustrated by these choke tube systems, because the tubes were hand picked for performance and the material is high-density tungsten, which flies true no matter the shape.
Tungsten Tube Rules
Several elements are required for a solid performing tungsten choke tube. I follow five rules when taking tungsten into the field.
Rule 1: Make sure the tube you're using is steel shot and tungsten/iron safe. That means a 7-14 stainless or a special hard steel construction. Check the packaging when you buy the choke.
Rule 2: Always try your steel-safe factory modified choke before buying an aftermarket tube, because it could be perfect for your gun/choke combinations. Modified chokes will react like a full choke with tungsten.
Rule 3: When buying a replacement choke for tungsten shot, select a choke tube that extends beyond the muzzle. In most cases, the "work" happens in the end section of the choke, and relieves the stress against your gun barrel when ultra-hard tungsten shot passes into the choke's forcing cone and becomes constricted under pressure.
Rule 4: Price is not the final indicator regarding how well a choke tube will perform. Many good chokes today are selling for less than $50. Even choke tubes in the $30 range can perform well with tungsten shot.
Rule 5: In many cases, a tungsten-safe choke tube will also shoot steel shot well. Don't pass over the option to shoot steel just because you're buying the choke as a tungsten shot delivery system.
* Based on single round counts, and best pattern of three test rounds fired. ( There were no unworkable patterns tested with these chokes.)
Tungsten shot is designed to carry energy well beyond the limits of steel shot. You should always be thinking about your shotgun's ability to deliver the mail well beyond the normal effective range of a standard steel shot load.
In some ways, tungsten shot in larger pellet sizes has almost no upper limit in terms of extended range or energy transfer on warm targets. For example, tungsten BBs will do damage well beyond normal range limits. Lacking that limit, setting a goal of just how far you're willing to press the extended range issue is a good idea when seeking a choke for general field use.
While hunting with Tyson Keller -- a South Dakota guide who is one of the top guns in waterfowling -- I observed almost everything in Canada goose kills harvested with Kent Fast Steel's high-speed BB steel shot. When I hauled tungsten into the field, the guys were impressed, but dead is dead, and no shot was about to be called by Keller unless the birds were backpedaling with feet down over the decoys.
Pass shooting can be a different animal, and real homework needs to take place to select a tungsten shot delivery system. For pass shooting, I opt for an ultra-tight core pattern with the bulk of my 40-yard payload inside a 20-inch core pattern.
Which chokes can deliver this performance level? I would consider several. My personal choke tube design in the Dead Ringer (Remington only) makes use of a full stripper ring matched to 7-14 stainless steel and an external stress design. I have, by definition, been a pass shooter all of my life. I cut my teeth pass shooting Canada geese in Rochester, Minn., when geese and hunters of the big birds were few and far between.
Pass shooting chokes such as the Carlson's full Black Cloud in a two-tube set, and even Mossberg's 835/935 X Factor Ported Waterfowl choke tube stand tall for longer-range work. Pattern Master is deadly, but stay with large shot sizes, or like other brands, shoot a new Black Cloud design.
Black Cloud chokes are a very workable alternative to making a pile of changes in tube types and designs. In other words, they eliminate hauling five or six choke tubes into the field for a day's work. Black Cloud chokes built and designed by the companies mentioned are close to the ideal one-tube-to-get-it-done systems.
Choke tube development has advanced so far that in some cases, it is hard to tell the difference between tubes while counting pellet hits on a pattern board. Chokes have evolved into a very uniform and effective part of the smoothbore delivery system.
L.P. Brezny is a ballistics expert from Piedmont, S.D.