Kent Cartridge: The Return of Bismuth Shot!
Back in September, 1993, professional ballistician Ed Lowry wrote of the ballistic potential of bismuth shot, noting that bismuth had a decidedly clear ballistic advantage over steel. As steel has only 70% of the density of lead, it was and is a problem: lower lethal effectiveness and a higher capacity for crippling. At the time, Lowry wrote that bismuth was the most promising alternative to steel with its advantage of 24% greater density than steel. Additionally, bismuth is a far softer material that cannot destroy shotgun barrels. In January, 1993, Ross Seyfried conducted evaluations of bismuth for Petersen's Hunting with positive results. The Lowry treatment of bismuth article should be considered an absolute must read and I've included it for your reference. LowryBismuth1993.pdf Ed Lowry concludes his treatise by saying, "When that happens, hunters will finally have have a substantially superior alternative to the current mix of wildly unpopular and ballistically inferior steel shot loads."
The early bismuth loads had manufacturing problems, with difficulty in producing pellets larger than #5 shot and brittleness of the shot itself. Kent has refined the manufacturing process, apparently addressed the brittleness, and the Kent Bismuth loads have just gone into production. The ideal shell for many applications looks to be Kent C122BNT36-4, which is a 2-3/4 inch shell, #4 shot, 1350 fps velocity, with a 1-1/4 oz. payload. It should be ideal for ducks and pheasants alike.
Above is the comparison I've run between the now-banned for waterfowl (and, in some areas, most everything) lead #5 shot at 1330 fps, the popular 3 inch unfolded length steel #2 1400 fps load, and the new Kent Bismuth #4 load at 1350 fps: all with 1-1/4 oz. payloads. The Kent Bismuth load soundly tramples the steel load in pellet count, gel penetration, energy, and energy density at 40 yards.
Unlike several molded composite tungsten shot types, the Kent Bismuth shot is spherical without the increased air drag of wide belts around the shot pellets. The four dollar a shot Hevi-Shot "Classic Doubles" shells (shown above) were some of the most pathetically poor patterning loads I've ever tested. If you cut open some shells like I did, the reason they stink it up so bad isn't hard to figure out. The "Classic Doubles" junk is no denser than bismuth, featuring not only truly abysmal patterns, but a ridiculous price as well.
Bismuth is choked essentially like lead and is safe for "lead-only" barrels and chokes, unlike many tungsten-based shot types. While many folks have been unhappy with steel and rightly so, due to the cost of tungsten many higher density tungsten shells have to be priced at a level that many hunters have demonstrated that they are unwilling to pay, with the notable exception of turkey hunters. However, while the good stuff is rarely free, even the crummiest of steel shotshells are a very long ways from free, either. The Kent loads hit the bull's eye in price / performance ratio, for rather that the $4 - $5 a shot realm of some turkey loads, a 1-1/6 poz. payload of #5 bismuth runs about $17 for a box of ten in 12 gauge, roughly $1.70 a shell. The loads I'm using. 1-1/4 oz. of #4, runs approximately $2 a shells. Prices do of course vary for steel, I naturally have no control over that, but around $1 a shell for a "premium" steel load is not unusual.
Is a dollar a shell worth it to you for cleaner kills, less shots fired, more range, and less abuse to your shotgun than steel? For many hunters, I suspect that the answer is going to be "absolutely." As a practical matter, assume that you want a minimum of 1.75 inches for pheasant. It can't be exact, for gel penetration does not consider feathers, much less breaking bones it is a comparative tissue simulant for soft tissue only. And, of course, some judgment is involved as well, for there is a dramatic difference between a bird with vitals partially exposed as opposed to a pheasant-butt presentation that requires a lot more penetration to get to the goodies.
If you are using #2 steel at 1400 fps with those parameters, you're out of gas at 35 yards. With the lower-recoil 1350 fps Kent Bismuth #4 load, you're good past 41 yards. Number 4 bismuth has better penetration at all ranges than #2 steel. Additionally, a 1-1/4 oz. load of #4 bismuth has about 25% more pellets (24.5%) than 1-1/4 oz. of #2 steel as well. If you are sick of the poor ballistic performance of steel (and why wouldn't you be?), the new Kent Bismuth loads just made steel obsolete.
Copyright 2016 by Randy Wakeman. All Rights Reserved.