Unlike powder which burns very rapidly, the primer is designed to explode. The explosion of the tiny primer showers the powder with hot sparks and causes it to ignite.
MEC says their Steelmaster is the only shotshell reloader that comes specifically equipped to load steel shotshells and the bonus is that it works equally well for lead shot. The resize station handles brass or steel in either high or low base. The automatic primer feed is standard.
Early primer components were effective but terribly corrosive. Fulminate of mercury caused brass cases to become brittle. Potassium chlorate left thick deposits like common table salt inside a firearm, making bore cleaning necessary within hours.
Today, the #209 primer is the standard for shotshells, having thoroughly vanquished the slightly smaller Remington #157 about 40 years ago.
Modern ecological consciousness is making its presence felt even with shotshell primers. Lead styphnate, successfully used in primers for years, is non-corrosive, but the fear of non-degradable lead compounds in the environment may eventually eliminate its use, a clear example of change, not for shooting performance, but for its ecological consequence. Winchester now markets a non-toxic “Reduced Hazard Shotshell Primer” which lists, as its explosive ingredient, a 1- to 2-percent by volume chemical called Diazodnitro phenol. Winchester’s MSDS or Material Safety Data Sheet (rev. 01/01/04) quaintly notes, “Will explode with mechanical impact or shock.” On the other hand, Winchester’s MSDS (also 01/01/04) for basic lead styphnate (lead hydroxide styphnate, lead hydroxide 2,4,6 trinitroresorcinate), a more common explosive ingredient in primers today, notes also that it will explode with mechanical impact or shock. However, it also states that basic lead styphnate is a toxic explosive with known environmental dangers, and is known to cause cancer and birth defects.
Like powders, primers have a character that is all their own. Some burn longer and others burn with greater intensity. Some have a longer spark and produce heat over a much longer time – as long as several milliseconds lasts, that is – and this is referred to as the flame’s duration. In general, target loads do not need much spark, because the propellants are in the fast-burning, easily ignited category. Hunting loads, however, may require a great deal of primer boost and heat to get slow-burning propellants cooking. On a cold day, the need for tight crimps and warm primers can be critical to avoid sputtering ignition. For these loads, magnum primers were developed, an appellation that seems contrary to their typical application. Magnum primers are especially hot. Generally, however, magnum shotshells derive their power not from hotter primers but heavier shot payloads.
So do not fool yourself into believing that all primers are the same. They are not. Different primers produce varied results and cause distinct reactions as other shotshell components (type of powder, weight of load, shape of the hull) change. Although you would not want to have one explode in your closed fist, as the explosion would cause you permanent damage, by itself, a primer is not a significant pressure generator. While one type of primer produces minimal pressure in one load, another type might not. The same is true for maximum pressure. Except for this one thing – all arbitrary component-swapping creates new and unpredictable results – you cannot generalize about or substitute with primers. These small explosive elements and the energy they produce are a part of every load’s individual ballistic equation. Even if the pressure does not increase or decrease a great deal when you substitute the primer you have on hand rather than finding the primer you need, the balance created by a specific combination of components will suddenly be thrown off balance and the resulting load will be a below-average performer.
It is relatively easy to crank up the pressure in a load to well over 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
