Hey bj, nice to hear you are still getting good use out of the 6.5JDJ. Rolling with handcannons and not trying to over control them is a great start on technique. I never really "gripped" them much until after the shot/follow through, not until they were heading for or past the noodle.
I never got to shoot any of the big boys on the TC's that came around/later after I stopped shooting, ie the 480 Ruger, 500S&W MAG, etc, but I would have liked to - and mine would not have been braked.
But a 375 ported? Just makes them smorted! LOL With technique they do not need to be ported, IMO none of them do, just makes them louder fire breathing dragons than they already are. Was the same with my Encore 10" 416 Rigby unbraked, not much different than a 45/70 and so still very manageable one handed shooting 400gr pills on the heavier frame. I never used the 225Win based JDJ's for big game hunting, they were my long to extreme range P&V barrels where 200 was short range for them. Of them I probably liked the two 257JDJ's I had the best with the two 6.5's a close second. But in the states where legal to use they have all killed plenty of deer, pronghorns etc from the 226 to 7mm JDJ'son that case. Maybe even bigger with the larger cals... the 30 Merrill RPM's were elk killers on the same case.