Richard Sherman wildcat 7 short mag max, utilizing 7 saum as parent case, forms like an ackley crush fit, has 78gr capacity, runs 180s upto 3100fps, 195s at 2950. If your not wanting to fireform and get max fps with short throat life, go 28 nosler. Personally if I were making the choice and wanted standard mag speeds I'd run standard 7mag, using adg brass which holds pressure very well, you'll get north of 3000fps with a 24" tube and RL26 or N570 powder with 180s or 175 Bergers. I have a 26" sendero 1:8 proof 7mm barrel in the safe.......I'm up in the air as well. Look at long range hunting forum, pretty sure this question has been asked with 100s of responses there. I actually really like the 7 blaser mag, it's basically a 7mm wsm with a long neck. Or an elongated 7 saum, has a case length of 2.3" and holds about 82gr.