Reloading Series: Bullet Seating And Crimping

Introduction to Bullet Seating

Hi everyone, Caleb and Steve from Brownells here! Welcome back to our reloading series. Today, we’re going to discuss bullet seating, which is the final critical step in basic reloading. Once you’ve got your case primed and powder charged, the last thing you need to do is seat the bullet and apply the proper crimp. By the end of this video, you’ll have a complete cartridge ready to go. We’ll be covering this process for both 9mm pistol rounds and .223 rifle rounds, so let’s dive right in!

Setting Up for 9mm Reloads

First up, we’re going to work with 9mm cases. We’ve already expanded and charged these cases with powder, as we covered in previous videos, so now we’re ready to seat the bullet. Steve starts by inserting the 9mm shell holder into the press. We’re using a Lee Precision bullet seating die for this demonstration, which features a tapered bottom designed for use with an automatic bullet feeder.

Once the die is installed, Steve makes sure that the seating stem is backed off completely. This way, we can adjust the seating depth as needed. With a primed and charged case ready, we place a 9mm bullet in the case mouth, making sure it stays put thanks to the flared neck.

Adjusting the Seating Die

To adjust the die, Steve lowers the ram and screws the die body down until it makes contact with the case. At this point, he brings the bullet seating stem down until it touches the bullet, giving us a starting point. After seating the bullet partially, we use calipers to measure the overall length of the cartridge. If it’s not quite right, we make incremental adjustments until we reach the desired depth.

Once the bullet is seated correctly, it’s time to talk about crimping. The die we’re using can also apply a taper crimp, which is crucial for semi-auto pistol rounds like 9mm. The crimp irons out the flare in the case neck, ensuring smooth feeding and proper chambering.

How to Taper Crimp with a 9mm Die

If you want to seat and crimp in one operation, here’s how to set it up: With the bullet seated to the correct depth, back off the seating stem and raise the case into the die. Then, screw the die body in until you feel resistance, indicating you’ve reached the crimping area. Adjust until the crimp is just right—enough to remove the flare without over-crimping, which could deform the bullet.

After setting the crimp, lower the ram and readjust the seating stem to maintain the proper bullet depth. This way, you’re ready to seat and crimp in one pull of the handle. If you prefer to crimp in a separate step, Lee and other manufacturers offer dedicated crimp dies, which we’ll cover next.

Using Separate Crimp Dies

For those who prefer to seat and crimp in two steps, using a separate crimp die is a great option. Steve demonstrates with a Lee Carbide Factory Crimp Die, which has a carbide ring at the base. As the case passes through the die, the ring ensures that the brass is resized to chamber perfectly, ironing out any remaining imperfections.

To use the crimp die, back off the top adjustment and lower the case into the die. Adjust the crimping mechanism until you feel resistance, then tighten it down to apply the perfect crimp. This method is especially useful if you’re using cast or coated bullets, as it minimizes the risk of shaving lead or damaging the bullet.

Setting Up for Bottleneck Rifle Cartridges

Next, we move on to .223 rifle rounds, which have a bottleneck case. The process here is similar but with a few variations, especially when it comes to precision. We’ve got options from Hornady and RCBS for seating dies, each with unique features. Steve starts by explaining the Hornady sleeved seating die, which helps align the bullet for better accuracy. The die uses a sliding sleeve to guide the bullet into the neck of the case, minimizing the risk of misalignment.

Hornady and RCBS Die Options

For even more precision, we look at an RCBS micrometer seating die. This die has a window that allows you to drop the bullet in from the side, a feature that’s both handy and efficient. Steve demonstrates how to use the micrometer to fine-tune bullet seating depth. The micrometer adjustment is great if you’re loading different bullet weights, as you can note the settings for future reference.

Steve mentions that if you’re loading for an AR-15 or any rifle that feeds from a magazine, crimping is a must to ensure reliability. The RCBS die can seat and crimp in one step, or you can use a dedicated crimp die if you prefer more control.

Adjusting for Precision Loads

If you’re loading for precision, such as in a bolt-action rifle, you might choose not to crimp at all. Instead, you can rely on the neck tension created during case sizing to hold the bullet in place. However, for magazine-fed semi-autos like the AR-15, crimping is highly recommended to keep the bullet secure during feeding and recoil.