How to Reload 40 S&W Ammo

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Smith & Wesson is a major American firearms manufacturer. Among their products is the .40 S&W ammo made with Winchester. Although most Americans now use 9mm ammo, the .40 S&W ammo is still widely popular. If you find one, you definitely should know how to reload 40 S&W ammo.

How to Reload 40 S&W Ammo

Reloading a 40 S&W ammo is the same as any straight-walled pistol cartridge. Some people claimed that reloading is dangerous. However, if you follow the published 40 S&W Ammo reloading manual, you should be safe and your firearm functioning.

Reloading a .40 S&W ammo

There are various steps to take when reloading 40 S&W ammo.

  • Prepare and clean the brass: use a bucket or tumbler and a colander. You can use any bowl with medium-sized holes if you don’t have a colander. Place your brass into the colander and shake it to remove dirt and residue. You can also use a cartridge case cleaner.
  • Sort out cracked and damaged brass: remove any brass that has cracks or damage. This may cause failure to fire and can even lead to damage to your gun.
  • Punch out the old primers and resize the shells: use a deprimer tool or reloading press to punch out old primers. Most deprimers also resize shells so you are good to go.
  • Reprime the 40 S&W ammo: reprime your ammo using a primer tool. It’s important to install the primer because it’s the device responsible for initiating the propellant combustion which pushes the projectiles out of the gun barrel.
  • Load gun powder into the shells: make sure you have a die set, reloading press, and powder scale, and calipers. The dies push the cartridge case into the reloading die and screwed in place into the reloading press. Follow the manual on how much gunpowder to fill up the shells. Make sure to have the exact measurements as too little or too much can be dangerous for you.
  • Seat the bullet into the casing: press the bullet into the casing using a reloading press. Make sure to measure the cartridge length before this using calipers. The cartridge length is important to not overpressure the ammo.

Just remember to follow all the specific instructions on the 40 S&W. Make sure you follow the exact numbers written on the manual or you could end up with fatal injuries when using the ammo.

What Is 40 S&W Ammo?

The .40 S&W is a rimless pistol cartridge made collaboratively by Smith & Wesson and Winchester. Law enforcement mainly uses the 40 S&W ammo. The design duplicates the performance of the Federal Bureau of Investigation’s 10mm Auto cartridge.

Rows of ammunition lined up

You can also retrofit the .40 S&W ammo into medium-frame for 9mm automatic handguns. This explains that even with the current popularity of the 9mm ammo, the 40 S&W is still common among most gun enthusiasts because you can also use them for 9mm handguns.

Is It Cheaper to Reload 40 S&W?

If you compare reloading 40 S&W to new factory ammunition then reloading is a lot cheaper. However, it also takes up much of your time. The process of reloading can be tedious and you need to be precise and accurate with measurements. One mistake could lead to a malfunctioned gun or even fatal injuries.

The 40 S&W ammo isn’t a picky round. Reloading it is fairly easy like most straight wall brass. You must have the right amount of neck tension to hold the bullet. If anything, the bullet would eat up most of the cost for reloading.

When reloading 40 S&W, you have to choose which is more important to you, time or money. However, if you have tools such as a reloading press, then it wouldn’t take up that much of your time.

What Is the Best Powder for Reloading 40 S&W?

Most mid-range pistol powder works well with 40 S&W ammo. Some gun owners use specific powders for its effect on your shots. Some use faster powders for more low recoil and slow velocity. Other gun owners use slower powders for maximum velocity.

Bullets stored in an open box

Does 40 S&W Use Small Pistol Primers?

The 40 S&W uses a small pistol primer. The FBI designated it as one of their primary small pistol ammo. S&W downsized the 10mm full power so that it meets the FBI’s medium velocity specification. This results in less powder and more airspace in the case.

How Many Times Can You Reload 40 S&W Brass?

It depends on the condition of the brass. Factors such as max load. Most gun owners would tell you to use the brass until they look damaged. Some gun owners even reload their 40 S&W for as much as 20 times.

It all depends on how well you handle the brass and how careful you are with the reloading process. Nickel-plated only lasts for about 5 – 10 reloads but brass can go beyond 20.

The usual first sign you see on a damaged brass is when it splits at the mouth. Once you spot those, disregard reloading that brass.


Reloading 40 S&W is a cheaper alternative from buying new ammunition from the gun store. Although, it can be time-consuming, the process of making your own ammunition can be fun in its own way. Make sure you follow the published manual correctly and have the exact measurements to avoid any accidents.

James Forrester is a lifelong gun and firearms owner, and an even bigger advocate for gun safety. He created with the purpose of sharing helpful tips and educating others on how to keep guns and weapons safe and secure.