Glad that has worked well for you! But the truth is that the accuracy you speak of is for your gun only. All guns don't have the best accuracy at max loads. And there are plenty of accurate loads that don't use 150 gr in most guns. Also, just to be clear on what we are talking about, powerbelts are not considered sabots. They are basically an undersized full bore, pure lead conical.

There are a ton of reports out there of failures when you push a powerbelt that hard. At 25 yards, that bullet going that fast will come apart if it strikes anything substantial. Fact is would actually get better penetration/terminal performance from that bullet at less than 100 yards with lower powder charges.

So, IMO you have a great 200 yard combo! But since the vast majority of shots I take are less than 100 yards, and I have never taken a 200 yard shot with a muzzy, I will stay with lower charges. This combo is obviously right for you, but if I had that load in my gun with a buck of the woods stepped out at 20 yards, I would have a nagging worry in the back of my mind.