Necking down 6.5x47 brass featured

Necking Down 6.5×47 Lapua Brass

In Blog by Rich10 Comments

This week’s article is on necking down 6.5×47 Lapua brass. There’s been a good bit of interest in this caliber in general. Some folks are put off by the idea of working with a Wildcat cartridge. It typically means there is some extra work to do in order to have brass ready to go for that caliber. I’m here to tell you that the brass preparation with 6×47 Lapua is exceedingly simple and pretty quick to perform. I’ll show you just how fast you can do it as well as describe the steps involved along with any that may come later in the process. Ready? Let’s get started!

What’s a Wildcat?

Just to refresh the memories of those in the know, or as an introduction for the uninitiated…a wildcat is a non-standard caliber. Regular calibers have support from the industry and are listed in SAAMI or CIP indexes. A cartridge will be listed in those indexes so a set of safe standards exist for companies that plan to load quantities of ammunition for that chambering. This way you can be assured that a box of 308 Winchester will work in your rifle, your dad’s rifle, and even your buddy’s rifle. All of which makes things safer for folks just buying ammo off the shelf. A wildcat chambering doesn’t have that set of standards for how hot it’s loaded, case length, etc.

Necking down 6.5x47 lapua brass starting

Cases 1 & 2 are brand new, with a 6.5mm bullet resting on top, the third case on the right is already sized to 6mm with a 105gr Berger resting on top

6×47 Lapua is a wildcat cartridge off it’s parent cartridge, the 6.5×47 Lapua. The only difference between the two chamberings is ┬áthe case neck diameter. The 6.5×47 Lapua has a neck diameter sized for 6.5mm (.264) projectiles. The 6×47 Lapua has a neck sized for 6mm (.243) size projectiles. The process of necking down a case is what you would perform in order to take the 6.5mm neck and size it down for a 6mm bullet. There are different ways to go about it but the nice part about the 6×47 Lapua is that it’s a one step operation!

Necking Down 6.5×47 Brass

It’s this simple. In order to neck the full size cases down so they work in the 6mm Wildcat variant of the cartridge you have to run the case up into a full length sizing die. You might ask why use a full length die when all we need to size is the neck? The reason has to do with how neck dies and bushing dies function. They tend to size most of the case neck. However, they don’t size the entire neck. The other problem is my experience has shown me that a partially sized neck tends to lead to inconsistent neck tension. This manifests itself as bullets seating to inconsistent depths in the case as the cases are loaded. It becomes a pain in the ass. It means constantly readjusting the seating die and measuring loaded cases.

Necking down 6.5x47 Lapua brass sized

Here the two cases have been through the die and you can see a Berger 6mm Hybrid resting on the neck of #1 and how the larger 6.5mm bullet rests above the neck on #2

The full length die sizes more of the neck than a bushing die and gives a much more consistent tension along the entire length of the neck. This way when I go to load the cases for the first time I can set the micrometer seating die to the overall length I’m after and keep seating bullets. I don’t have to worry about the loaded rounds winding up with inconsistent overall length. The process of actually necking the cases down is as simple as it sounds. All I have to do is run the cases through the sizing die once and they come out ready to go.

Other Considerations

There are some things to consider. One of which is crushing the shoulder. The way to avoid this is by lubing the cases prior to necking down the cases. This way you avoid the possibility of crushing the shoulder. Once the shoulder collapses as you size the case you’ve pretty much wrecked it. Even without case lube I’ve only had this happen a few times. Counting on one hand number of times. So it’s not something that happens often, but at $1/Case Lapua brass isn’t cheap. I’d rather avoid it altogether. That’s why I recommend lubing those case necks!

Necking down 6.5x47 lapua brass crushed

Two crushed shoulders on 6.5×47 Lapua brass, you want to avoid this

I also will occasionally see a flairing of the necks after they come out of the die. The cases will chamber in my rifle at this point but I like a nicely formed case after necking down 6.5×47 Lapua brass to 6×47 Lapua. What I’ll do is run the formed brass through the Giraud trimmer after sizing. This trims all the cases to the proper length as well as deburring and chamfering the necks. So essentially I can form the 6.5×47 Lapua brass into 6×47 Lapua brass in two steps total. A single pass through a full length sizing die and a quick trip through the trimmer!

Wrapping Up

So to wrap this all up, it’s a pretty simple process for necking down 6.5×47 Lapua brass and forming it into 6×47 Lapua brass! It’s a single pass of the 6.5×47 brass through a full length sizing die. Afterwards a quick pass through a case trimmer makes the operation complete and the brass is ready for loading. I’ve seen no difference in accuracy between brand new brass freshly formed and brass that’s already been fired and resized. There are plenty of wildcat chamberings out there in the world that have different things to offer the shooter. However, before you start putting a rifle together with a wildcat caliber, consider this. Make sure whatever the process is to prepare brass for the chambering that you are comfortable with the work! If you have additional questions or anything to add, do so below in the comments!

Owner and Proprietor of AccuracyTech, LLC. Rich is a Firearms Enthusiast, Precision Rifle Competitor, and Writer. He is committed to bringing readers quality reviews and articles related to the Precision Shooting Sports. If you have any questions for him, please use the contact form on the site.


  1. Thanks for report I have bushing dies in other calibers so you think FL dies are better overall than bushing dies?

    1. Author

      Not at all, I love bushing dies and prefer them. For necking these cases down the first time, though, a full length die works better.

  2. How would you neck it down if you only had a Full Length Bushing die?

    1. Author

      I wouldn’t recommend it, Kevin. It’s easy to collapse a shoulder or leave a big portion of the neck unsized. A Forster FL die isn’t expensive. Better to order the right die and do it correctly from the get go.

  3. Will you please tell me the three dies you would use. Sorry but I was just wondering specifics. So run 6.5×47 brass thru Forster FL (6 or 6.5) die. Then run it thru a Redding FL Bushing die, then the micrometer seating die?
    Sorry but can you clarify it for me? I’m new to this.
    Thank you

    1. Kevin,

      I have been researching the same process. My plan is a FL die first, then a FL bushing die, followed by the micrometer seating die. On this cartridge I don’t think I will ever resize only the neck due to tension considerations. As for the dies I am leaning toward Redding on everything, but have been told the Wilson dies are excellent as well.

  4. Do you know if this same process would work for converting Lapua 6.5mm Creedmoor brass to 6mm Creedmoor? By same process I mean just running the new cases through a full length Forster 6mm Creedmoor die. Thanks.

  5. Hi Rich,
    I have just started this process using a Whidden FL non bushing die. I have noticed the die misses the last 0.035 of the neck before it meets the shoulder ( creating a small false shoulder). Do think this will course any problems ?

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