AR-308 – Brass and Brass Prep Basics

Now that we’ve finished provisioning the LR-308B rifle for the AR-308 project, it’s time to gear up for precision handloading! Before we start loading, we need to get brass, and prep that brass. It turns out that for precision rifle loading, much of the labor and attention to detail is really related to the brass. If we were building a race car, it would be analogous to making sure we had a strong and precision-built frame that would have the correct geometry and be tailored for our racing application.

Step 1: Choose your brass

The first thing one needs to do is to decide what brass to use (one type or multiple types). For 308 Winchester cartridges, the good news is that you can go with once-fired military brass (very abundant!) or choose non-military brass. If your goal is utmost accuracy, you’ll need to fire the cases in your rifle regardless of whether you choose military or non-military brass. If you buy new brass, you can buy high-end brass (Lapua, Norma, Nosler, …) and just use it, or you can buy common-grade brass (Winchester, Remington, …) and do more prep up-front.

For the AR-308 project, I’ll be using two types of brass- once-fired Federal 7.62x51mm purchased online, and also Norma 308 Winchester brass that I already loaded for another project but have not yet fired.

Step 2: Fire-form and prep your brass

Once we have brass in hand, we need to get our brass prepped and fire formed. Some would argue that fire forming is not necessary for a semi-auto rifle like our LR-308B, but I like to fire form regardless of the rifle, and use once-fired cases as reference to precisely size the cartridges. That way you know what you’re starting with and can use your rifle’s chamber as a “baseline”. For this semi-auto rifle, we’ll be full-length sizing the brass, so we won’t have to worry about chambering issues.

For prep, we’ll be looking at things like sizing/decapping, trimming, cleaning and reaming primer pockets, and more. This prep is time well spent for sure. Once we are done with prep, we can then move on to sorting. I’m taking the approach here to start with absolute precision/consistency for our initial loads, and we can then loosen things up (especially when we start to load on progressives) and compare the results with our clean “baseline” of our single stage loads.

Step 3: Sorting the brass

Sorting the brass will help with consistency. Sorting by weight to ensure consistent volume, and also sorting by neck thickness (and consistency) to make sure we have uniform neck tension and proper bullet to bore alignment for our various lots of precision loaded ammo.

I found this great article on the accurateshooter.com site: AccurateShooter.com article on tools for measuring neck walls

If you give that article a quick read, you’ll have a good background understanding of why we want to sort our prepped brass for these precision loads. Heck, we can take our “rejects” and use them for plinking too… For this project, we’ll be using the Redding Case Neck Gage – I’m looking forward to using this new tool to make these loads perform their best- it will be satisfying to know more about the loads I’m producing.

So that’s our game plan for brass prep. It’s going to be fun!

 

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One thought on “AR-308 – Brass and Brass Prep Basics”

  1. GAVIN

    I JUST FINISHED THE AR-308 Precision Loading ARTICLES .
    VERY INFORMATIVE. I HAVE A ROCK CHUCKER PRESS USED FOR PISTOL
    ROUNDS. I NOW HAVE TWO NEW RIFLES A SAVAGE 111 LRH IN A 300 WIN MAG
    AND A SAVAGE 12 VARMINT IN A 22-250. I WAS WONDERING IF YOU COULD GIVE ME
    A LIST OF THE TOOLS YOU USED IN THE ARTICLES FOR FOR MY RIFLES.

    THANKS
    STEVE KLOSSING

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