Initially, this was going to be two separate articles, but I figure both methods are closely related; it would be best to put all the information in one write-up.

Selecting the correct bushing and mandrel size in the reloading process contributes significantly to accuracy.

Now would be the time to up your caffeine intake until you can feel your teeth vibrate because you won’t want to forget this information.

Before we begin, you will need to remove the mandrel (button) from your full-length die. If you decide against this advice, you may stop reading because these methods won’t work for you.

Method one

Using a dummy round for measuring purposes, grab your set of calipers. Measure the neck diameter of your case with a bullet inserted. You will now have your starting number.

Example:

The diameter of my case neck with a loaded bullet reads .309.

Let’s say I want three-thousandths neck tension (.003).

I simply subtract .003 from .309; this leaves me .306.

My bushing size, then, is .306.

Note: You may need a custom-size bushing if you have neck-turned brass.

Method two

This process sets your neck tension with the use of an expander and full-length bushing die.

Use a full-length bushing die to reduce your outside neck diameter. I generally select a bushing size of .003 under a loaded round.

Example:

I select a bushing size of .306.

Next, I selected a mandrel size for my desired neck tension.

I use a .282 mandrel in an expander die and expand the case.

That’s it; now, when I seat my .284 bullet, I will have .002 neck tension.

The cool thing about this method is that you can dial in what works for your rifle by experimenting with mandrels of different sizes. Some companies even offer lengths in four decimal places (e.g., .2825).

Conclusion

I realize that these how-to articles I write seem complicated at first. However, you’ll learn this one isn’t once you try these methods.

Before you ask, the answer is yes—I will be making video versions of these articles at some point. They will be coming soon. Many people, myself included, are better visual learners. Be patient.

Remember, shoot better than me.

Disclaimer: Reloading/handloading can be hazardous to your health like many things in life. You take full responsibility when performing these procedures. 5 Gun Nation is not liable for your decisions. Don’t be an idiot, and if you are, it is not our problem.

5 Gun Nations How-To series