November 20th, 2020

New SAAMI Cartridges: 277 SIG FURY, 6.5 WBY RPM, 6.8 Western

.277 SIG Fury saami cartridge specification 80000 psi

The Sporting Arms and Ammunition Manufacturers’ Institute, Inc., (SAAMI), has announced the acceptance of three (3) new cartridges for SAAMI standardization: 1) 277 SIG FURY; 2) 6.5 Weatherby Rebated Precision Magnum (WBY RPM); 3) 6.8 Western. While the 277 SIG FURY was developed originally for the U.S. Military, it should serve well for hunters, as will the new 6.5 Weatherby RPM and 6.8 Western. SAAMI has standardized the dimensions, max pressures, and load specs for all these three new cartridges.

277 SIG FURY from SIG Sauer

Developed by SIG SAUER for the U.S. Military, the 277 SIG FURY boasts a SAAMI maximum average pressure of 80,000 psi, driving a 135-grain bullet to 3,000+ fps. That 80K PSI pressure is WAY higher than almost all other cartridge types. To achieve these high pressures, the 277 FURY uses a hybrid case with a brass body and harder alloy metal case head. This design allows the cartridge to run very high pressures. Dan Horner of SIG Sauer told us: “When the handloaders get hold of this brass, it will be a game-changer for sure”. We envision this cartridge could be necked down to 6.5 mm and it would dramatically out-perform the 6.5 Creedmoor. And yes the official name of the cartridge is all caps “277 SIG FURY”.

LINK: 277 SIG FURY official SAAMI Cartridge and Chamber Diagram (PDF)

.277 SIG Fury saami cartridge specfication 80000 psi

.277 SIG Fury saami cartridge specfication 80000 psi

6.5 Weatherby Rebated Precision Magnum

Developed by Weatherby, the 6.5 Weatherby Rebated Precision Magnum (WBY RPM) was introduced with a maximum average pressure of 65,000 psi, with a 140-grain bullet traveling at a velocity of 3,075 fps. The 6.5 WBY RPM offers signficantly higher velocities that most other 6.5mm cartridges, including the 6.5-284 and .265 Win Mag. SEE 6.5 Cartridge Comparison Table

LINK: 6.5 Weatherby RPM official SAAMI Cartridge and Chamber Diagram (PDF)

6.5 weatherby rebated precision magnum cartridge WBY RPM SAAMI

6.8 Western from Winchester

Developed by Olin Winchester, the 6.8 Western was introduced with a maximum average pressure of 65,000 psi, with a .277-caliber 175-grain bullet traveling at a velocity of 2,840 fps. A shorter variant of the Winchester Short Magnum (WSM) family, the new cartridge appears to be about .090″ shorter than the .270 WSM. It has the same 35-degree shoulder angle as the .270 WSM.

LINK: 6.8 Western official SAAMI Cartridge and Chamber Diagram (PDF)

6.8 western rebated precision magnum cartridge western .270 wsm SAAMI

For additional information on these new cartridge designs and other recently accepted cartridge and chamber designs, visit SAAMI.org.

Permalink Bullets, Brass, Ammo, Gear Review, News, Tech Tip 6 Comments »
November 20th, 2020

Access 11 Years of Shooting Sports USA Stories — All FREE!

Shooting Sports USA competitive shooting high power marksmanship archive SSUSA

Enjoy the Shooting Sports USA Archives
With the COVID-19 restrictions we’re all spending more time indoors at home. For some folks that means long sessions in front of the boob tube. Here’s a better idea — there’s a vast resource of great gun-related content available online for FREE. Check out the Shooting Sports USA Articles Archive. SSUSA maintains a vast digital library with hundreds of articles going back to June 2009.

Shooting Sports USA competitive shooting high power marksmanship archive SSUSAIt’s easy to find back issues of Shooting Sports USA magazine. Here’s how: Using the gray toolbar at the top, click on the “ARCHIVES” icon in the upper right area (indicated with red arrow). When you click on “ARCHIVES”, a window will open with a selection of Shooting Sports USA magazine covers/dates in a vertical column.

Next use the vertical scroll bar to go from November 2020 (the latest issue) all the way back to June 2009. Click any issue cover to read.

Shooting Sports USA competitive shooting high power marksmanship archive SSUSA
The June 2020 issue features a Palma rifle built with Eliseo Tubegun Chassis System.

How to Find and Save Articles
To search through back issues, select “MORE OPTIONS” from the toolbar. Then click the “SEARCH” button. When that opens, select either “Search archives” for ALL back issues or “Search Only this Issue”. When you’ve made your choice, enter your search term(s). For example, you can search for “Camp Perry” or “Palma” or “F-Class Championship”. You can also save any archived issue as a PDF for viewing offline. Just click “SAVE” to download the article you’re currently viewing/reading.

Shooting Sports USA competitive shooting high power marksmanship archive SSUSA

Read Sample Articles
Here are a couple of our favorite SSUSA feature stories from recent years. There are hundreds of other informative articles worth reading.

Wind-Reading Tips from Champion Shooters »

Shooting Sports USA Wind Reading tips

How to Clean and Maintain Match Barrels »

Shooting Sports USA Barrel Maintenance Clean Bore Scope

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November 20th, 2020

Smarter Reloader — Use Expander Mandrels with Your New Brass

Expander Mandrel reloading case neck tension cartridge brass

Before you load that nice new cartridge brass for the first time, run an expander mandrel down the case necks. This will iron out dents and provide more uniform neck tension. Chose a mandrel diameter that provides appropriate neck tension.

Lapua brass is so good that you’ll be tempted to just load and shoot, if you have a “no-turn” chamber. However, some minimal case prep will ensure more uniform neck tension. Keeping your neck tension very uniform allows more consistent bullet seating. That, in turn, usually yields better accuracy, and lower Extreme Spread and Standard Deviation (ES/SD). Lapua brass, particularly 6mmBR, 6.5×47, 6.5 Creedmoor, and .308 Win comes from the factory with tighter-than-optimal necks. Before you seat bullets, at a minimum, you should inside chamfer the case mouths, after running an expander mandrel down the necks. The expander mandrels from both Sinclair Int’l and K&M will both leave the necks with enough neck tension (more than .001″) so you can then seat bullets without another operation. We suggest putting a bit of lube on the mandrel before running it down the necks — but remove any lube that gets inside the necks before seating bullets.

Sinclair Expander Tool Mandrel

Both Sinclair and K&M Tools make a die body specifically to hold expander mandrels. The Sinclair version, is shown above. This $32.99 unit fits caliber-specific expander mandrels ($9.99) which measure approximately .001″ less than bullet diameter for each caliber. This is an updated “Gen II” design that completely captures the mandrel within the die so the mandrel cannot pull out. It also has an O-ring in the die cap that allows the mandrel to self-center within the case neck. Sinclair now offers three sizes of die bodies for expander mandrels: .17 -.338 Caliber (#749-011-715WS $32.99); .357 – .50 caliber (#749-008-843WS, $32.99), and a special .50 Cal die body for large-diameter 50 BMG presses (#749-009-163WS, $39.99). All Generation II dies are machined from stainless steel and the standard diameter 7/8-14 dies include the Sinclair Stainless Steel Split Lock Ring.

Once you run the Sinclair expander mandrel down the necks of Lapua brass, after you account for brass spring-back, you’ll have about .002″ neck tension*. This will make the process of seating bullets go much more smoothly, and you will also iron out any dents in the case mouths. Once the case mouths are all expanded, and uniformly round, then do your inside neck chamfering/deburring. The same expander mandrels can be used to “neck-up” smaller diameter brass, or prepare brass for neck-turning.

Forum member Mike Crawford adds: “These expanders can also reduce runout from offset seating. Prior to bullet seating, expand the sized necks to force thickness variance outward. With the Sinclair system, the necks will springback fine, and will not be pulled out of center. This leaves plenty of tension, and bullets seated more centered. I do this, even with turned necks, to get improved seating.”

Mandrels vs. Expander Balls on Decapping Rods
If you haven’t acquired an appropriate expander mandrel for your brass, but you DO have a full-length sizing die with an expander ball, this will also function to “iron out” the necks and reduce tension. However, using a die with an expander ball will work the necks more — since you first size them down, then the ball expands them up again. Typically (but not always), run-out is worse when using an expander ball vs. an expander mandrel.


* This .002″ tension is what we have observed with Lapua 6mmBR, 6.5×47, 6.5 Creedmoor, and .308 Win brass. This might vary with much smaller or larger cases, and of course a different brand of brass might yield different results. If you get too little tension with your current mandrel, you can get a smaller-diameter mandrel from 21st Century Shooting. 21st Century even offers low-friction Titanium Nitride-coated mandrels.

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