A standard 7RM will push a 180 @ 3K when throated properly 26" barrel, 7 Blaser will do same maybe a little faster, only downside is single source brass, but it is tough/consistent stuff. 7mm off wsm case will do similar speeds. 7mm-300 win will push 180 @ 3150, adg makes excellent brass and is very easy to form with 300 win FL bushing dies barrel life would be 1500+- depending if you keep cool. 7mm saum on built on long action with 26" barrel will do 2900+ and have great barrel life. 7mm sherman will push 180s around 3k too, but brass is $$. All these velocities are top end, high psi loads. I have a hells canyon 1:8 carbon barrel on order and I'm trying to decide same question. I've shot the nosler out to 1800y and made hits on moa sized target in spendy custom rifles. It's a performer but you'll get 1000+- rounds and it'll be done. The Sherman case design is very minimal taper and 40° shoulder. I've pondered taking the blaser or saum case and giving it the same treatment. The blaser imp will run 3150 with 180s, already been done. It hold about 86gr capacity, smack between the 7RM/WSM & 7-300wm. I'd think a 7saum imp would hold 76gr and get 3050 with 180s. Adg makes the Sherman cases, and will have 7mm and 6.5mm saum brass after January. Their brass is top notch. My suggestion, build your rifle chambering around quality source of brass, that'll be available for a long time, or buy 300-400 cases at the start. Supposedly Peterson will have wsm brass available in 19, that makes the 7-300/270wsm a candidate, as norma is somewhat soft. I hope some this info is useful and doesn't muddy the waters.