Looking forward to this as well.
To me, it almost seems like the 6.5G big brother if it can push the 230 ELD-X at a decent speed. JBM says the 230 ELD-X stays supersonic to just over 1,000 at 2k elevation with a MV of 2,200 fps. The only downside is obviously trajectory (13.4 mils to 1k vs. 12.1 mils for the 6.5G). Both these cartridges are within 0.5 mil to 750 yds. This comparison only gets better if the 8.6 can shoot the 230's faster. It can obviously shoot heavy subs as well.
The 375 Raptor seems much more like the AR10 version of the 300blk. Heavy subs for <100 yds and supersonic capability to 200-250 yds.
For comparison, I used the 6.5 Grendel shooting a 130gr Berger at 2400 fps. Everything at 2k elevation.
Would love to hear more thoughts / comparisons. Very curious how fast the 230's will be pushed with this cartridge. I'd love a 12.5" large frame that is as versatile as this cartridge seems. Maybe some companies will make some 338 bullets better suited for this cartridge? The 230 ELD-X seems like the best to me but if I'm missing something I'd love to hear it.