Sorry for the confusion. I will shoot steel with it enough to practice for that rifle but will use the 6.5x284 for my primary steel shooter
lightbulb I commend your gentlemanly response(s) to the replies by those less so. lightbulb
As you're going to use this rifle primarily as a LR hunting rig and shoot steel only as practice (having a dedicated rifle for that) I would choose the 7mm STW over the 28 Nosler. My choice is not because the 28 Nosler is not a powerhouse - it has demonstrated significant hammer-ability.
I'd choose the 7mmSTW if only because it has been around a quite a long time so dies are already readily available at reasonably affordable prices.
The greater question is brass availability, but with so many other die-hard STW aficionado's you will be able to network to source it quite easily.
However, and as Wildrose wisely stated, Nosler will likely support the 28 Nosler for many years to come and that's no factor to ignore.
Performance-wise, I don't know the differences between the 28 Nosler and the 7mm STW though I doubt it is significant. Whereas the difference btw the 7mm Rem Mag and the other two is significant.
With these super-fast hotrod chamberings, barrel life is not going to be as long as the milder ones, but the performance is there if you wanna pay for it!
7mm STW would be my recommendation for you. gun)