Winchester advertises that its AA hull will “become the new benchmark of reloadability.” In the same ad, the Illinois company suggests that you can achieve at least 15 reloads from a single shell. Fifteen is a lot of reloading. Not only is the hull subjected to violent extremes of heat and pressure, but also the crimp must fold and hold precisely all of those times. One of the biggest problems in reloading is forcing yourself to discard hulls that may not be in the best shape. Winchester AA hulls have an excellent reputation among reloaders.
Nothing is going to work better for you – either in your reloading press or in your shotgun – than perfect shells. Many writers recommend that you begin reloading with a bag of new or even once-fired and pre-sorted shells that can be purchased from your local dealer or via a known internet vendor like Cabela’s. Unfortunately, it is well known that most shotshell reloaders use hulls well past their prime and wind up trading performance for economy. No one would consciously choose to make this trade, but we reload in part to make our money and our components last longer than one shot and there is always that push-pull dilemma of getting “just one more shot” from a hull.
Petals on G/BP wads are designed to snap-away from the flying shot after it leaves your muzzle. According to Ballistic Products, this allows the pattern to expand evenly out to the fringes.
Fortunately, hulls occasionally give you easily discoverable clues about their readiness for retirement. Worn-out shells destroy shot-to-shot consistency. As hulls age, patterns and velocities can be affected by pressure fluctuations, so it is crucial that you quickly identify and dispose of flawed hulls. Inspect the base and walls of hulls for cracks and corrosion. Hulls with compromised structures will leak gas and cause the loss of pressure and velocity.
Hulls begin to fatigue with their first loading. Repeated reloading and firing eventually causes the seal between the base of the paper or plastic hull and its brass base, or the seal with the base wad, to deteriorate. In some hull types, the process of base degradation can be rapid and extreme, and therefore more noticeable than in others. Other symptoms of hull fatigue include plastic walls becoming brittle near the top or at the crimp and finally, developing hairline cracks that leak gas. You must toss these hulls immediately.
THE PRIMER
Beginning at the bottom of the hull, after re-sizing, your reloading press next extracts the spent primer and inserts a new one. Former editors of this book compared a loaded shotshell to an automobile engine; both required only a spark to begin the transformation from inertia to explosive power.
Struck by your gun’s firing pin, instantly super-heated, the tiny amount of chemical inside the primer in the base of a shell explodes. This supplies sudden, intense heat to the propellant by driving tiny white-hot particles upwards into it. The burning particles launch the propellant on the brief but glorious arc of its burn.
For maximum efficiency and effectiveness, a primer must offer the precise heat that a particular propellant load needs. Bulky, slow-burning powders for instance require a specific type of flame to ignite and burn properly. Too much heat and flame unnecessarily raise early chamber pressure, thereby “pushing the cycle.” Insufficient heat and flame do not ignite a large enough portion of the propellant for pressure to rise sufficiently before the chamber is decompressed by the load’s movement and the decreasing confinement.
The story of the primer began in about 1807 when Scottish hunter and inventor A. J. Forsyth discovered that a particular mixture of chemicals produced an explosion when it was struck. He realized that if the reaction was contained and channeled, it could be used to ignite powder charges and he eventually used his knowledge to create what was called a “pill lock” ignition system. His was the first step along the way to today’s modern primers and the path wound through England and America for more than a hundred years.
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