Swaging 223 Bullets from 22LR Brass with a Blackmon Swaging System – Chapter 2 – Making Cores

Swaging 223 Bullets from 22LR Brass with a Blackmon Swaging System – Chapter 2 – Making Cores

In chapter one of this series we made some brass jackets out of discarded .22LR casings using the Blackmon jacket swaging die.  In chapter two, we’re going move on to the next step in the process of swaging bullets; making lead cores.

What are Cores?

When swaging bullets, cores are used as the raw material that’s eventually shaped into a projectile either with or without a jacket. The core making process is also the single most important step of bullet swaging, as it’s used to control the weight and size of the bullet, both of which are essential to consistency and accuracy.

Casting Cores

There are two ways of making cores including cutting them from lead wire, and casting them with a special mold.  I don’t have access to lead wire, so I opted to cast my cores.  The mould shown in the video above was custom made for this purpose using a standard Lee Precision blank.  As you can see, it takes a six-cavity handle set, and includes a sprue cutter, making it simple to use.  Below each cavity is an adjustment screw; these are used to control the size of the cores, allowing for a wide variety of bullet types.

The first thing we’re going to do is drain any leftover wheel-weight alloy from the melting pot, and replace it with pure lead.  Unlike conventional cast bullets, cores have to be cast from pure lead for several reasons.  For starters, lead is extremely soft, which makes the swaging process much easier, and eliminates the chance of damaging or breaking dies which can occur with harder alloys. Working with pure lead also ensures the cores consistently weigh the same so long as their volume doesn’t change.

Once then pure lead has been melted, casting can finally begin.  As you’ll see in the video above, the process is identical to casting any other bullet.  We simply fill the cavities, cut the sprues, and dump the cores.  Since we want our cores nice and soft, we won’t be quenching them at all– instead we’ll let them air-cool.  Cores also don’t have to be filled out 100% completely since the swaging process will compress them into nearly perfect cylinders.  For this reason, a bit of wrinkling isn’t a concern so much as the weigh the same in the end.

Now that we’ve got a good number of cores cast up, we can move on to the next stage, weighing.

Selecting Jackets

For this session I’ve decided to produce a standard, 55gr .223 bullet.  For this to work, we need to determine how much our jackets weigh, so we can customize our cores to make up the remainder.  22LR casings actually differ in weight from brand to brand by as much as several grains, so I’ve gone ahead and sorted these accordingly and selected Winchesters for this batch of bullets.

With the jackets sorted it’s time to perform some measurements.  As you will see in the video above, these Winchesters are coming in between 9.9 and 10 grains.  For simplicity of mathematics, we’ll call it 10.  That means we need to produce a core weighing 45 grains to make up the difference and bring us to 55.


With the jackets selected and weighed, it’s now time to begin processing the cast cores.  For this we’re going to be using the core swage die set.  As depicted in the video, this die set consists of three components including the punch, die and ejector.  Basically, a raw, cast core is placed into the die and then forced against the punch.  This causes pressure to build until lead begins to compress and eventually bleed off through the holes you see on the side of the die, bringing it down to the correct volume (and thus weight).  This also serves to smooth out any areas of the core that hadn’t filled or shaped quite right, leaving us with a much nicer looking core.

Installing this die set in the Blackmon press is simple, if a little counter-intuitive.  Whereas most swaging systems move the punch into the die, the Blackmon system actually works in reverse, by moving the die towards the punch.  This allows the swager to adjust the punch depth rather than the die position when determining how much lead to remove.  To install, simply thread the die and ejector into the ram of the Blackmon swaging press, then place the punch in the opposing end, and secure it with the retention nut.


With the die set installed, we’ll select a core, apply a bit of swaging lube to it, and insert it part way into the die (lined up with the punch).  As the handle is actuated and the punch and core meet, the swaging process begins to take place.  The core is slowly compressed into a perfect cylinder, with the excess lead forced out of the bleed holes in the die.  This waste lead can be reclaimed for subsequent castings later.

With the process completed, we’ll raise the swage press handle again, and remove the newly swaged core.  Using our scale we can see it weighs in at exactly 45 grains.  The first time you do this it will take several tries before you get right, however once the settings are dialed in they can be repeated over and over without adjustment.  Now that we know the punch depth is set correctly, we can go ahead and produce hundreds of cores in very little time.

In our next article, we’ll seat the cores into our jackets, and then commence point forming.

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