Editor’s Note: George Secor, a member of Delta Waterfowl’s board of directors, has taken some of the guesswork out of shell selection by undertaking an in-depth study of lethality of different loads.  George examined the ballistics of 513 different offerings, and from that list came up with the 70 most lethal non-toxic mallard loads for ranges beyond 35 yards.

Secor’s complete data base and unedited text, along with instructions for computing the efficiency of your favorite load, are available at by clicking here.  To find out if the load you use is meets the energy density and coverage criteria for the shots you typically take, visit our web site.

Delta Waterfowl encourages hunters not to take shots beyond their effective range, even if the load they’re using is capable of bringing down ducks beyond that range.

Revealed: The Most Lethal Mallard Loads
How to Find the Best Load for Your Shooting

By George Secor

The number of optimum loads for any type of waterfowl hunting is likely proportional to the square of the number of hunters in the discussion.

Much of the confusion probably stems from the great variety in loads now being offered.  The possible combinations of gauge, shell length, load weight, velocity, pellet size and pellet material add up to a staggering number.

Because no individual could physically test even a small percentage of the offerings, this paper uses mathematical criteria based on practical considerations for the ideal mallard load.  These criteria are designed to result in bagging 90 percent of the time. This study is restricted to mallard loads because the terminal ballistics for mallards has been thoroughly studied and the results are readily available in literature.

Before we begin, however, there are a couple of caveats that must be addressed.  First, good field craft trumps superior ballistics every time.  The shotgun shell hasn’t been developed that can compensate for poor shooting skills or the inability to get ducks into shooting range.  It’s critical that hunters hone their shooting skills and resist taking shots at birds beyond their effective range.

Further, it’s very unlikely that two different barrel-choke-load combinations will pattern with identical results.  To determine the exact coverage efficiency of your favorite load, it will be necessary to pattern-test your gun and choke with that load.

There are a number of loads that didn’t make the “pass list” that are effective at distances closer than the 35-yard minimum used here.  By knowing the patterning characteristics of your favorite load in your gun, whether it passed or failed, you can use the tables to determine the effective range.

For a load to be lethal, it must contain enough pellets to provide adequate coverage of the target (see Coverage Factor) at whatever distance the hunter is shooting, and those pellets must have sufficient energy (see Oomph Factor) to bring the bird down. The oomph is a function of the weight, size and velocity of the pellet.

Increasing the pellet’s mass generally implies reducing the number of pellets in the load, which decreases the coverage.  Increasing the velocity of the load can imply a reduction in load weight and hence a reduction in pellet coverage.

The Catch 22 is finding the right balance between oomph and coverage.

I’ll be the first to admit that the criteria to determine the optimum load are somewhat subjective.  However, the criteria are based on extensive lethality data collected on over 4,400 mallards, and the coverage criteria are based on the practical experiences of clay target shooters and the morphology of the mallard.

Methodology

A data base containing 513 loads was developed from information found on the web sites of the major manufacturers of waterfowling ammunition.  The shells run the gamut from 10-gauge down to .410 bore using seven different pellet materials with shot sizes ranging from T (.20 inch) to No. 8 (.09 inch). 

Five lead pellet loads, which are no longer legal for waterfowl, were included for the purpose of comparison to the non-toxic materials.  One of these is the Winchester Super-X 1 ½ ounce, buffered No. 4’s, which was the standard to which all other mallard loads were compared until lead shot was banned.

Although the data base contains 513 different loads, it would be inaccurate to claim it includes every currently available non-toxic load.  It does not include loads from the smaller companies in the United States or most shells made in Europe and imported to the US. 

It also should be pointed out that shells do not always behave as advertised.  This is particularly true of pellet counts and three-foot velocities. 

The Results

Of the 513 loads tested, 440, or 86 percent, were rejected for failing one or both of the established criteria detailed below.  Many of the “failed” loads—the .410 and 28-gauge—were never intended to be used for ducks, nor were some of the loads with very small or very large pellets.

Keep in mind that virtually all of the loads will cleanly kill mallards under the right conditions.  But only the ones that made the “pass list” can be counted on to kill 90 percent of the time at distances greater than 35 yards.

Of the 73 loads that passed, only 70 are waterfowl loads, the other three being lead loads used for comparative purposes.  There are no degrees of passing or failing, no just-missed or “almost passed”.  Those determinations are left to the discretion of the reader based on the range of the shots they take.

Eight loads qualified in Class 1, which means they had sufficient oomph (Energy Density) and coverage at distances greater than 45 yards.  There were 21 loads in Class 2, which means they had sufficient ED and coverage between 40 and 44 yards.  Class 3 loads were effective at distances ranging from 35 to 39 yards, and 41 loads made that designation.  (Hunters who limit themselves to 30-yard shots may find that loads not on the list also are sufficiently lethal.  See instructions with chart.) 

The Kent Cartridge Company topped the list of manufacturers with 22 passing loads—19 Impact Tungsten Matrix (ITM), two Fasteel and one Hevi-Steel.  Remington had 14 HEVI-Shot loads on the pass list along with one steel load.  The Bismuth Cartridge Company had 17 loads on the list, Federal had eight steel and five tungsten-iron loads that passed and Winchester had three steel loads.

Most of the 70 loads that made the pass list were 12-gauge (55), but nine 10-gauge, four 20-gauge and two 16-gauge loads also qualified.

Of the 12-guage loads that made the pass list, 22 are 3½ -inch, 19 are 3-inch and 13 are 2 3/4-inch.

Of the optimum loads listed, 18 were No. 4 shot and 20 were No. 5.  Those two pellet sizes represent 54 percent of the loads on the list.

The three-foot coil velocity of the optimum mallard loads ranges from 1,220 to 1,550 feet-per-second, while the mean velocity is 1,358 fps and the median velocity is 1,340 fps.    

Here’s a look at how we determined which loads made the list.

The Lethality Model

In order to kill a bird cleanly and bring it to bag, I would argue that at least one pellet must penetrate and disrupt the function of a vital organ or critical bone.  The vital organs include the brain, spinal cord, heart and lungs.  The critical bones include the vertebra, the upper wing bone and possibly the lower wing bones. Collectively, the vital organs and critical bones make up what is defined in this article as the critical area.

Even a major disruption of the vascular system may not halt the bird’s immediate flight, and a duck that flies several hundred yards into dense cover is rarely retrieved.

There is one argument that says the hydrostatic shock effect of multiple hits will bring a bird down, but other studies dispute that claim.  The best argument for multiple hits is to raise the probability that at least one of those pellets will penetrate and destroy a vital organ or critical bone. 

The Oomph Factor

Tests conducted by the Olin Corporation at Nilo Farms in Illinois and the US Fish and Wildlife Service at Patuxent, Maryland almost 40 years ago compared the effects of lead shot to steel and copper shot on mallards.

In both tests, the birds were “flown” in a harness across the line of fire and the shot was triggered electronically so the bird was perfectly centered in the pattern.  Carefully thought-out criteria were applied to determine the number of birds that were bagged, crippled and lost, or that survived.

The shooting distances ranged from 30 to 80 yards at generally 10-yard increments.  Nilo tested four loads while Patuxent used three.  One hundred mallards were used for each load/distance test, with 4,400 birds used by both groups.

The external ballistics of the seven Nilo and Patuxent loads are documented or can be readily calculated.  The load/distance combinations that produced bagging percentages of between 95 and 99 percent were selected to develop the threshold energy density (ED).

The Nilo No. 4 steel, No. 4 copper and No. 6 steel loads and the Patuxent No. 4 steel load met the bagging criteria at 30 yards.  The Nilo No. 4 buffered lead load met the criteria at 40 yards.  The mean pellet Energy Density for those five loads at the distances noted is 235 foot-pounds/square inch.

Will energy density of less than 235 ft-lbs/in2 kill mallards?  The answer is “yes”, but not at the 95 percent or higher probability level.  The consequence of straying too far below the 235 ft-lbs/in2 level is increased crippling, and no ethical hunter wants that.

The conclusion is that pellets must have minimum ED’s of 235 ft-lbs/in2 to be considered lethal at the 95 percent probability levels.  The final step is to determine the distance at which the pellet’s ED achieves 235 ft-lbs/in2.

I’ve decided to use 35 yards as the minimum distance for the pellet’s ED to achieve a minimum ED of 235 ft-lbs/in2.  This distance stretches the average kill distance, which is about 30 yards, but honors the fall-off in pellet energies in the 40 to 50-yard range. 

Thus, loads in the data base having ED distances of less than 35 yards will be rejected.

The Coverage Factor

The development of the Coverage Factor is a complicated four-step process.  First, the size of the target must be determined.  Size is defined as the cross-sectional area of the vital organs and critical bones, not the size of the feathered bird as it appears to the hunter. 

In the case of the mallard, the size is 12 square inches, about the same area as a circle 3.9 inches in diameter.

In order to assure that at least one pellet hits that target 95 percent of the time requires that an average of almost three pellets hit the target.  Given a 12 square-inch target, that means the pellet density must be about .25 pellets per square inch, or one pellet per four square inches.

To give the shooter a little room for aiming errors and based on clay target experiences, it was decided to require the pellet density of .25 pellets per square inch to extend over a circle with a minimum diameter of 19 inches. 

It also was decided that maximum pattern percentage would be 90 percent—that is 90 percent of the pellets in the load falling on or within a 30-inch circle.  It can be shown that the load must contain a minimum of 188 pellets to meet that criterion.

It’s entirely possible that a given load will have sufficient ED out to 40 yards, but failed to make the list because it lacked coverage at that distance.  It’s also possible that a load has ample coverage to 50 yards, but loses the necessary ED at 40.

Finding a load that maintains the energy and coverage for the hunter’s average length of shot is the key.  Using the tables provided by clicking here will allow hunters to make that determination.