Squashing Brass: The Basics Of Resizing Rifle And Pistol Cartridge Cases

A .40 S&W resizing die (left) Note the carbide ring. The .223 Remington resizing die on the right has the decapping rod extended to show the case mouth expander ball.

A .40 S&W resizing die (left) Note the carbide ring. The .223 Remington resizing die on the right has the decapping rod extended to show the case mouth expander ball.

Every time you pull the trigger, lot’s of violent things happen inside the chamber of your gun.

  • The primer ignites.
  • The primer ignition sets flame to the propellant, which then begins to burn at an obscenely fast rate. It doesn’t technically explode (unless you’re using black powder) but it burns so fast you might think it’s exploding.
  • As the propellant burns, the chemical reaction creates high pressure gas, which has to go somewhere – fast.
  • This swelling gas cloud inside your cartridge does two things. First, it expands the brass cartridge case until it’s pressing against the inside walls of the gun’s chamber. Then, it pushes the projectile hard enough to overcome the friction of the cartridge case mouth and launch it down the gun barrel.
  • As the bullet leaves the cartridge, and the pressure starts to drop, the brass cartridge case starts to shrink back closer to it’s original size – but not all the way.
  • The cartridge case mouth will be opened up a bit as a bullet that was comfortably seated there has just been violently ejected.

All of this happens in a split second and is the reason that, when reloading your own ammunition, you need to resize the brass cartridge case using a resizing die. While resizing the cartridge case rarely compresses it to it’s original size, it will crush it back within cartridge dimension standards, allowing it to chamber in any gun of the proper caliber.

Resizing Dies

A resizing die is simple a carefully shaped hunk of metal that is used to “press” the empty cartridge case back to standardized dimensions. The brass cartridge case is forced into the interior of the die with a reloading press and the internal shape of the resizing die presses the brass back into the proper dimensions.

Think of this process as making a hamburger. You take a misshapen pile of ground beef, and using pressure from the outside, you shape it into the desired form. With fired brass, you take a cartridge case that has contained a massive conflagration, and therefore expanded in size, and press it back into shape. Unlike the hamburger, brass is hard, and tastes lousy, hence the need for a steel resizing die and a reloading press to apply the necessary pressure.

Brass is not as easy to “work” as hamburger meat, and significantly more pressure than available with bare hands is required to reshape it to standard size. Squashing a brass case into a steel hole under great pressure will almost certainly result in a unified piece of useless steel-brass metal as two parts are hopelessly stuck. Why? Unlike hamburger meat, neither brass or steel have yummy, slippery fat grease naturally available. So, when resizing brass, you need to have some type of lubrication.

Depending on the type of cartridge you’re resizing, this can be done in a couple of different ways. Let’s talk about how that’s handled in both straight wall and bottleneck cartridges.

Pistol Brass (Straight Wall Cartridges)

By “straight wall” I simply mean that the cartridge case is shaped like a cylinder that has the same diameter from the rim of the cartridge to the mouth. Like a toilet paper roll or aluminum soda can. Not all pistol cartridge cases are like this. A great example of an exception is the .357 Sig, which is shaped more like an old Coke bottle as it narrows as you get closer to the case mouth. In these rare cases, you need to resize it as you would a bottleneck rifle cartridge. We’ll get to that in a minute.

Even though most pistol cartridges have straight walls and resizing is minimal, lubrication is still required. This is where ingenuity comes into play. Some clever reloading engineer figured out that carbide is a little more slick than standard steel. If you could make a reloading die out of carbide, then additional lubrication would not be required, as the brass case won’t stick to the carbide material. Most reloading dies for straight walled cartridges have a carbide ring. As you pass the “ring” down the length of the cartridge case, it resizes as it goes – without grease.

Read the rest at OutdoorHub!

Talking Brass: How To Lose Your Frustrations At The Range

Someone figured out how to exercise their demons - with a .30-06.

Someone figured out how to exercise their demons – with a .30-06.

I’m a reloading freak. Because what’s better than tactical cooking? (Tweet This)

Anyway, I shoot at an outdoor range where lot’s of folks bring boxes of shiny, new, factory ammunition to shoot – and then they leave the brass lying all over the place.

Is there a “clean up after yourself” rant forthcoming? Not on your life. I love these folks. New, once-fired, name brand brass?

I’ll pick up new range brass faster than Alec Baldwin complains about his fame and fortune.(Tweet This)

After testing a new scope the other day, a Weaver Tactical 1-5×24, I cleaned up. Big time. First rate rifle brass sells for about 50 cents apiece. Heck, I’ll spend hours picking up someone else’s brass. And thank them for it.

Anyway, I was tired, and jazzed about the new scope, so I wasn’t paying much attention. When I got home to clean and sort my new treasure trove, I noticed handwriting on some of the .30-06 cases. Hmmm.

On closer examination, someone found a safe and fun way to vent their frustrations. At 2,700 feet per second.

And just what was this anonymous individual concerned about? From the ones I could still read, here’s the list of aggravations:

  • F— You _____.” Sorry, the last word was illegible. But this person sent some serious anger down range.
  • New slang” But no mention of Justin Bieber, which I found strange.
  • Something about “evil money.” Perhaps this person found the recent government stimulus programs lacking?
  • People who treat vets like shit
  • Kids that drive $60,000 cars
  • Dad’s B.S. – Not my problem!
  • Who I was
  • England

I kid you not. England.

If you’re a board-certified psychiatrist, we’d love a preliminary analysis. Sorry, but we can only pay for your services in used range brass.

Reloading Ammunition in 10 Easy Steps

Birth of a reloaded cartridge, from left to right: dirty, nasty, stinky range brass; shiny cleaned brass; spent primer ready for decapping; decapped brass; resized brass; re-primed brass; ready for powder charge; bullet seating (it's not fully seated here); the finished product!

Birth of a reloaded cartridge, from left to right: dirty, nasty, stinky range brass; shiny cleaned brass; spent primer ready for decapping; decapped brass; resized brass; re-primed brass; ready for powder charge; bullet seating (it’s not fully seated here); the finished product!

Now that the infinite gun-gasm known as SHOT Show is over, it’s time to get back to reloading! If you read the first article in this reloading series, “To Reload or Not to Reload: 12 Important Considerations,” and decided reloading might be for you, read on! Today we’ll talk about the basic steps of reloading brass ammunition, like common rifle and handgun cartridges. Shotgun reloading is fun and rewarding, too, but we’ll handle that as a separate topic as the steps and equipment are different.

First, the safety warning! I don’t have a lawyer, but if I did, he would tell me to tell you to exercise extreme caution when reloading ammunition. Always, and I mean always, follow printed loading recipes from major bullet, propellant, or reloading equipment manufacturers. They have lots of expensive testing equipment that ensures their published loading data is within safe pressure limits.

Okay, I feel less legally exposed now, so let’s get back to the fun stuff.

When you boil all the complexity down, reloading is simply recycling of fired cartridges—like plastic milk containers, but a lot less smelly. For most modern ammunition, a cartridge is made up of several components, some of which are expendable and others reusable. The only “directly” reusable component in a cartridge is the brass casing. Fortunately, that’s generally the most expensive component. Let’s take an insanely practical look at the steps involved in reloading rifle and handgun ammunition. We’ll walk through the process today and discuss the equipment needs next week.

Save the brass!

If there is the slightest chance you might take up reloading in the future, the very first step is to hoard brass. Yes, like that show on A&E. Hoard brass until your living room is knee-deep with the stuff and the dog can’t make its way to the kitchen. Why? You’ll need it. And it’s expensive. Every time you bend over to pick up a casing, think $0.10 to $0.75! You’d pick up a quarter or two every time you saw one on the ground, right?

Clean the brass.

Technically, you don’t have to clean brass cartridge casings to reload them, but I always do. Cleaning the brass helps you make nice, pretty ammunition that is sure to impress your friends. More importantly, it reduces the risk of your reloading dies getting all gunked up. Clean ammunition also feeds into your gun more reliably.

Deprime the brass.

The primer is one of the expendable items. Once it’s blown up, it’s no good anymore. Either a dedicated decapping die is used to punch the old primer out of the bottom of the casing, or more commonly, the die that resizes your brass will also knock the old primer out.

Resize the brass exterior.

When you fire a rifle or handgun cartridge, the whole brass casing actually expands in the chamber of the gun. As the pressure goes down when the bullet leaves the barrel, the brass shrinks back a bit, thereby allowing extraction from the chamber and ejection towards the person next to you. While it shrinks, it doesn’t shrink all the way back to original size. A resizing die is used to “encourage by brute force” the brass back into the correct exterior dimensions. This step ensures that your reloaded ammunition will fit back into the chamber of your gun and fire properly. If you reload bottleneck rifle ammo, you will also need to trim the case back to the proper length. All this mashing tends to make it stretch.

Read the rest at OutdoorHub.com!


Be sure to check out our latest book, The Rookie’s Guide to Guns and Shooting, Handgun Edition. It’s available in print and Kindle format at Amazon:

The Rookie's Guide to Guns and Shooting, Handgun Edition

The Rookie’s Guide to Guns and Shooting, Handgun Edition

Danger! Men Cooking!

Danger Men Cooking - Reloading

Danger Men Cooking

Legal Disclosures about articles on My Gun Culture