As we always do with new cases, I'm already eying a wildcat from this case by simply necking down to .257. It won't be as overbore as the 257 Wby, but more potent than the .25-06 AI. The main plus, perhaps, is brass is (as of now) between half and a third the price of .257 Wby or quality WSM brass. Unfortunately, it's Winchester brass, and I'm afraid that will doom it to fast obsolescence like the 25 WSSM if no one else picks up the ball on brass production. I can see where it will have use as a 6.5mm to perhaps edge out the PRC, 7mm to give a performance boost over the 280 AI without magnum-level blast and recoil, and even in .30 caliber to fill the gap between the .30-06 and .300 Win Mag at half the cost of the 300 WSM. I'm afraid availability will be the biggest issue in the short run, and brass quality being the biggest issue in the longer run. Just look at the 6mm Creedmoor. It outperforms the .243 all day long and has brass made by several quality manufacturers, yet there are only a couple of production rifles still manufactured in that chambering by our regular store-stocking manufacturers - and those are super expensive models. Lack of production guns and lack of brass (good brass) kill cartridges quickly.
For historical reference, see the SAUMs. Super accurate and easy to load, but only Remington made brass for a long time, then Remington stopped making their own cartridge. Fortunately, like the 6mm Creedmoor, target shooters had figured out just how inherently accurate these rounds were, and kept the demand for brass high enough that Norma, and now ADG has jumped on the brass bandwagon. The 6.8 Western, is for all intents and purposes a .270 SAUM. The only differences are a 5 degree sharper shoulder angle, a few thousandths less taper, and a few thousandths shorter culminating in about a grain and a half higher case capacity. I like the design, and I think if someone tried to figure out how to "improve" a SAUM case, this would have to be it. Essentially, the performance will be practically indistinguishable from a 7 SAUM case necked down to .277. They are trying to neuter the cartridge by providing 24" barrels, when clearly, this cartridge with the heaviest bullets for caliber will need to burn very slow propellants (ideal use for your Reloader 26 and H1000!). A 26" barrel will be a must to get all the performance out of this round. I see the 150gr Berger being the optimum bullet for this round as configured, good to 750yards on deer and elk with a much better muzzle velocity and still really good BC retaining the energy necessary for clean, quick kills. Any builds not offered over-the-counter will require a special twist barrel that many great barrel manufacturers don't offer (yet?). It would be a 1:9 for me to use the 150 Bergers and 160 Partitions, and that's as high as I'd go. In the .257 version, it would be throated for the 115 - 120gr boattails and also twisted 1:9, which is a custom order, even on a custom barrel. There may actually be some merit for the .257 version to utilize the 130+ grain target bullets now available. There should still be enough velocity to make it worthwhile. That would need an even faster twist. I produced a 6mm and a .257 version of the 7 SAUM some years ago, and the .257, especially, was a beast! It almost equaled .257 Wby speeds with 10 - 14 grains less powder. Accuracy from my prototype was around 1/2 MOA with 5-shot groups. This version could be even slightly more efficient!
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