Reloading for Shotgunners. Rick SappЧитать онлайн книгу.
the acceptable and safe prescribed pressure with just a primer swap. From a reloader’s point of view, this is the least desirable change. Tests indicate that some common target loads can change by as much as 3,500 psi with only a change of primer.
Here is a minor example from the 10-gauge tables of changing results from simply changing a primer. A quick search through the load data in this book will give you many more such examples. Let us hypothesize that you are using a single stage press to load 1-5/8-ounce lead shells and you have Blue Dot powder and Remington SP10 wads on hand.
Using a CCI 209M primer, the recipe calls for 45-grains of Blue Dot for an achievable velocity of 1,285 fps and a maximum chamber pressure of 8,000 psi.
Using a Winchester 209 primer, with the same 45-grain Blue Dot powder load gives you the same shot velocity – 1,285 fps – but raises the pressure in the chamber by 10 percent to 8,800 psi.
As of November, 2004 you could expect to pay between $95 and $100 for a case of 5,000 Remington, Winchester or Federal Primers or about $90 for Cheddite primers. On a per shot basis, this is about 2¢ or less.
THE WAD/SHOT CUP
Once you drop the powder in a hull, it is time to insert the “wad.” Now, a wad is a wad is a wad. Right? Of course, you know that could not be the case. If everything were that easy, we would not need books like this to guide reloading. A wad is a necessary and curious item in a shotshell. On the one hand, it is very simple and on the other hand, it is crucial to good, consistent performance.
I have said “it” as if there is a single wad that every handloader now uses, but that is not the case. In fact, during the past 150 years the wad has evolved as much as any other component of a shotshell. One way it has evolved is from paper or thick circlets of felt and cardboard to plastic, and now it is progressing toward special biodegradable materials such as those from Kent/Gamebore mentioned earlier in the chapter. Another way that it has evolved is from a flat disk or several stacked disks to … well, a pair of opposite facing cups with a springy cushion connecting them. Let’s talk about wads.
All primers are not the same. Not even all primers designated for shotshells are the same and they can not be interchanged without double checking load formulas. Many primers look alike and if you load multiple gauges, or multiple types of guns, keep your primers strictly separate.
The wad has two primary functions. It seals the powder from the shot and prevents the burning gas from leaking through the balls of shot or around the sides and thereby diminishing the unitary force of the shove down the barrel. Obviously, it must fit smoothly and with great precision against the sides of the hull, not so tight that it causes undue pressures from the burning powder, but not so loose that it does not completely seal off the gas.
Because the cardboard and felt wad circlets of a hundred years ago have evolved into a much more impressive and functional shotcup, the wad itself has accrued additional functions. By cupping the shot, it prevents significant contact between the accelerating pellets and the smooth steel of the barrel. Although this might leave residue inside the barrel for you to clean out later, lead would not damage the barrel.
Steel shot however has been known to scratch older barrels made from soft, relatively thin steel and to damage barrels with fixed chokes. There is certainly a question about some of the new pellet formulations, such as Federal’s tungsten-iron, which are designed to improve upon lead. Some of these products are harder than lead and are actually harder than the steel in the average shotgun barrel.
By minimizing contact between your steel barrel and the pellets in a load, the shotcup helps keep the accelerating pellets away from the hard barrel. The friction from such contact causes soft pellets to deform; it gives the otherwise relatively round pellets flat spots and these deformed pellets are pattern-wreckers, the so-called “flyers.” Thus, one function of a modern century wad or shotcup is to protect the pellets, and that is something a flat cardboard disk from the early 1900s could not do.
The Deci-Max is designed for extending 10-gauge versatility with lightweight shot charges and small shot sizes. It is pre-slit and recipes are available for this wad with lead, bismuth and Hevi-Shot.
The Competition Special 12-gauge wad from BPI is recommended for high performance shooting value on sporting clays courses. It features a double-crush section of “G” ring to cushions pellets during the setback phase of a shot.
Hevi-Shot requires wad columns or shotcups specifically designed for loading and shooting Hevi-Shot. The TPS 10-gauge shotcup series represents a culmination of many convergent technologies.
Once the shotcup has exited the barrel, it falls away quickly. Most modern wads are designed with petals so that the shotcup opens like a flower, the sides folding quickly backwards. Air resistance causes the shotcup, its petals now open like a parachute, to fall behind the pellets almost instantly. The wad usually falls to the ground within 10 to 15 yards, having completed its mission. (Older or experimental shotcups without petals often fell to the ground with some pellets remaining inside!) Un-slit wads (i.e., those without precut petals) are available, but with the intent that the reloader will slit them to a particular load and pattern preference.
What the old style flat disks could do, however – and what special disks can still do (refer to some of the recipe notes) – was to provide bulk when needed as reload recipes for powder and payload changed. Only one shotcup is used in a load today, but felt or cardboard wads can still be stacked if necessary when shell components change.
In separating the burning powder from the lead shot, the wad or shotcup helps prevent the extreme heat of the burning gas from melting the lead. Lead melts at 621.5 degrees Fahrenheit and boils at 3,164 degrees. According to Mike Daly at Hodgdon, today’s smokeless powders generate heat in the range of 2,800 to 3,200 degrees Kelvin. That computes to a range of 4,575 to 5,300 degrees Fahrenheit. That is easily hot enough to melt your lead shot if the temperature is sustained for more than a few seconds, which of course it is not. It is hot enough to fuse some of the pellets if these hot gases slip around the wad and decide to mingle. Imagine the havoc this will wreak with your carefully constructed shot pattern. Disastrous!
Curiously, reports on Hevi-Shot from Environ-Metal and Remington, show quite a bit of pellet deformation before a load is shot and this has not seemed to disrupt the patterns profoundly. Hevi-Shot is a blend of tungsten, nickel and iron that is actually heavier than lead – and still eco-friendly. This commentary should not be construed as a commercial for Hevi-Shot, only a report about characteristics that appear to differ from the normative expectation, but hunters and load testers alike attest to the lethality of this brand and composition. On the other hand, Kent/Gamebore notes that their Impact brand eco-friendly tungsten-matrix shot is not formulated to improve on lead. Thus, it is not harder than the steel in the typical shotgun barrel and does not require thick, protective plastic shotcups. Kent says its tungsten loads are just fine for fixed-choke guns as well as for sub gauges and guns with screw-in chokes and that these loads have the same “clean killing ballistic properties of lead.”
Another function of the wad/shotcup is to provide a flat, regular surface against which the expanding gases can press outward. A load of shot, even target #9, is porous, and buffered shot, which is only a load of shot whose spaces between the pellets are filled with sifted polyethylene particles, will allow gas to blow through unevenly if the shot is not backed by a wad or shotcup. The wad provides a ceiling against which the hot, expanding gas can press evenly, thrusting the shot down the barrel uniformly.
The wad also seals the gases behind the shotcup in an area