As a side note to that chart, I'm running between a 10-12 BHN alloy for my cast HP's. In the .357 I am loading some 160gr HP's to just over 1300fps from the 6" barrels on my GP-100's, and around 1450'ish out of the 8" Contender with no ill effects.
These are all plain based, sized to .358" and either lubed with either Carnuba Red or powder coated. Either way works well, just depends on how lazy I am feeling when I get ready to load some.
So for your loads, I would simply work up slowly in small load increments and only load 5-6 rounds at a time with each increase. Shoot them one at a time and inspect the barrel as you go. I use a white piece of paper to light up the bore. I open cylinder and slide it in between the frame and use the sun or a flashlight to light it up. Soon as you reach the max load or you start to see the streaks going all the way down the barrel that it your top end.
This is what you hope for, good for the amount of rounds and the loads being shot.
This one had over a hundred rounds through it at the time of the pic.
This is what you don't want, not good under any circumstances.
This was after only 4 rounds. So you now have something to compare to. I knew when I loaded them that I was probably going to get this, but I had to try it anyway. This was the same alloy I used in the upper revolver only the velocity was increased by about 250 or so FPS. After changing the alloy a touch however I was easily able to get the same results as the first pic using the higher loads.
Thing is your only going to find the sweet spot for each alloy by testing it to see what it will handle. Your barrel, the size, the lube, and the load your pushing it with, is all combined to reach the end result. If one of them is faulty or not up to the task, the results will be like the second pic in most cases. Maybe not as bad, but if you start to see a goodly amount of it heading down the barrel you might as well stop and inspect what might be the issue. A little isn't anything to worry about as in the thin streaks in the upper pic. That is fairly normal or at least what I consider normal after a hundred rounds or so. It doesn't build up any more than that, and in some other barrels it doesn't even get to that.
I would go into the details of cause and effect, but it is already put in a MUCH better layout than I could muster up on the link right here,
Chapter 7 - Leading -- The Cast Bullet Nemesis, By Glen Fryxell
I highly recommend that you read through that and even pull down the entire PDF copy of that booklet. Glen is a VERY knowledgeable fellow on the subject of cast bullets and getting them downrange like they should be.
Oh and all this, and I didn't even ask, which way did you end up using to up the size on your bullets?