Shotshells 101

If you've never taken a shotshell apart, or your are just curious, here's a little education for you.

This is a cutaway of a common target shell, specifically a Winchester AA.

The hull is made of plastic and includes a plastic "base wad".  The "base wad" is the lower structure of the shell.  Federal still uses a wound paper base wad, but most other manufacturers use plastic.  That's why Federal shells smell different when they are shot.

Anyway, the "brass" portion of the shell is actually not brass anymore.  It is steel that is plated with brass or zinc or some other metal to keep it from rusting.  Target loads usually have short brass, while shells made for hunting have high brass.  According to Lee Precision, the length of the brass no longer has anything to do with the hull's ability to withstand whatever load you wish to load into it.  Indeed, there are shells out there that have no brass at all.

All shells use the same #209 primer.  There are magnum 209A primers that are supposed to add a little more fire to the load.  I have used them and see no practical difference in the loads I made.  I'm sure they may have added a slight increase in pressure, but for the loads that I make, they are not necessary.

Shotshell powders are made for a wide variety of gauges.  Most of the powders out there are suitable for anything from 28-10 gauge.  The .410 is an odd ball.  There are just a few powders produced for the diminutive cartridge.  Most shotgun powders are also suitable for pistol loads.  Some of the cheap promo loads have powders that burn dirty.

The Wad is where things get different.  In the old days wads were simple fiber discs that separated the shot from the powder and offered some cushion to keep the shot from deforming.  Today, things have changed dramatically.  The one piece plastic wad you see above is the most common design in target shells.  This design does a few things.  It separates the shot from the powder and provides a seal as it moves down the barrel.  It also acts as a shock absorber to cushion the shot during firing.  This keeps shot from being deformed.  Round shot flies true, deformed shot does not.  It also offers a cup to contain the shot.  Once out of the barrel this cup opens up and the shot begins to spread.  This not only keeps shot from contacting the barrel, but also can extend range.  There are so many different types of wads out there that it would be hard to discuss them here.  Just look at the wide variety manufactured by claybuster alone.

Not all wads have the shock absorber.  

Finally there is the shot itself.  Most shot is made of lead, with a small amount of antimony mixed in to harden it.  Lead shot is coated in graphite to keep it rolling around free.  If you dissect a high end hunting shell marketed for pheasants, turkeys, etc. you may find that the shot is plated in copper.  This is done to stop the shot from deforming as it accelerates down the barrel.  Noticing a trend here?  The faster you want the shot to go, the more the shot tends to deform.  Plating the shot in a hard material gives it a hard egg like shell.  Some loads even have buffer material to further protect the shot from damage. 

 

Lead is not the only choice in shot.  Far from it.  Non toxic shot was mandated by federal waterfowl regulations many years ago.  Steel has been the go to material as it is cheap and plentiful.  It is however not very dense and must be pushed to high velocities to make clean kills.  This lack of density also gives steel the tendency to bounce.  That effects the way that steel shot goes through a gun's choke.  Whereas a duck hunter using lead probably would have used a full choke, a hunter using steel would have no luck at all with that full choke.



Steel's inherent disadvantages were quickly realized by hunters, who demanded something that worked like lead, but didn't poison the waterways.  Enter tungsten, hevishot, bismuth, and other heavy materials that approximate the weight and density of lead, but are non toxic.  Some of these are actually heavier than lead.  I personally have never spent the money on any of that ammo.  I'm a target shotgunner primarily, so lead does just fine by me.