February 13th, 2017

Lapua 6.5 Creedmoor Brass Has Arrived at Graf & Sons

Lapua 6.5 Creedmoor cartridge brass

The most hotly-anticipated cartridge brass, the new-for-2017 6.5 Creedmoor cases from Lapua, arrived late last week at Graf & Sons. With the strength and uniformity for which Lapua brass is famous, this new brass should definitely “raise the bar” for 6.5 Creedmoor and 6mm Creedmoor shooters. Note — the new Lapua 6.5 Creedmoor brass features a small flash hole and small primer pocket. As of 9:00 am Monday morning this brass is in stock at Grafs.com priced at $119.99 per 100-ct box, with a max order of five (5) boxes.

UPDATE: The 6.5 Creedmoor brass sold out after we posted this story. But there will be more coming. You can ask Graf’s to be notified as soon as the next shipment arrives.

Lapua 6.5 Creedmoor cartridge brass

TECH TIP: For those who have been loading Hornady or other-brand 6.5 Creedmoor brass with large primer pockets and large flash holes, you may need to reconfigure your reloading tools. Check your sizing die — you may need to change to a smaller-diameter decapping rod. In addition you’ll need to use a small primer size “pusher” on your priming tool.

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June 1st, 2014

How Cartridge Brass is Made — The Inside Scoop

When we first ran this story a while back, it generated great interest among readers. By popular request, we’re reprinting this story, in case you missed it the first time around. — Editor

Rifle cartridge brass manufacturingPrecision shooters favor premium brass from Lapua, Norma, or RWS. (Lake City also makes quality brass in military calibers.) Premium brass delivers better accuracy, more consistent velocities, and longer life. Shooters understand the importance of good brass, but many of us have no idea how cartridge cases are actually made. Here’s how it’s done.

The process starts with a brass disk stamped from strips of metal. Then, through a series of stages, the brass is extruded or drawn into a cylindrical shape. In the extrusion process the brass is squeezed through a die under tremendous pressure. This is repeated two or three times typically. In the more traditional “draw” process, the case is progressively stretched longer, in 3 to 5 stages, using a series of high-pressure rams forcing the brass into a form die. While extrusion may be more common today, RWS, which makes some of the most uniform brass in the world, still uses the draw process: “It starts with cup drawing after the bands have been punched out. RWS cases are drawn in three ‘stages’ and after each draw they are annealed, pickled, rinsed and subjected to further quality improvement measures. This achieves specific hardening of the brass cases and increases their resistance to extraordinary stresses.” FYI, Lapua also uses a traditional draw process to manufacture most of its cartridge brass (although Lapua employs some proprietary steps that are different from RWS’s methods).

RWS Brass Cartridge Draw process

Deep-Draw Ram Illustration from Demsey Mfg.
deep draw cartridge brass animated gif

After the cases are extruded or drawn to max length, the cases are trimmed and the neck/shoulder are formed. Then the extractor groove (on rimless cases) is formed or machined, and the primer pocket is created in the base. One way to form the primer pocket is to use a hardened steel plug called a “bunter”. In the photos below you see the stages for forming a 20mm cannon case (courtesy OldAmmo.com), along with bunters used for Lake City rifle brass. This illustrates the draw process (as opposed to extrusion). The process of draw-forming rifle brass is that same as for this 20mm shell, just on a smaller scale.

20mm cartridge brass forming

20mm Draw Set Oldammo.com

River Valley Ordnance explains: “When a case is being made, it is drawn to its final draw length, with the diameter being slightly smaller than needed. At this point in its life, the head of the draw is slightly rounded, and there are no provisions for a primer. So the final drawn cases are trimmed to length, then run into the head bunter. A punch, ground to the intended contours for the inside of the case, pushes the draw into a cylindrical die and holds it in place while another punch rams into the case from the other end, mashing the bottom flat. That secondary ram holds the headstamp bunter punch.

Lake City Brass bunter

The headstamp bunter punch has a protrusion on the end to make the primer pocket, and has raised lettering around the face to form the headstamp writing. This is, of course, all a mirror image of the finished case head. Small cases, such as 5.56×45, can be headed with a single strike. Larger cases, like 7.62×51 and 50 BMG, need to be struck once to form a dent for the primer pocket, then a second strike to finish the pocket, flatten the head, and imprint the writing. This second strike works the brass to harden it so it will support the pressure of firing.”

Thanks to Guy Hildebrand, of the Cartridge Collectors’ Exchange, OldAmmo.com, for providing this 20mm Draw Set photo. Bunter photo from River Valley Ordnance.

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