I don't think that 147 gn slug expanded, I think it was the pressure in the jug that blew out the side of the jug. 147 gn slugs from a 9mm don't really move that fast to expand as they should, they penetrate more than expand. Also, I feel the silicone filling retards expansion, not enhances it. I shoot a 147 gn cast truncated .356 diameter slug from my 38 Super at around 1140-1150, and don't look for expansion but penetration. I'll bet that if you can load a 155-158 gn .356 cast slug in your 9mm, at about only 1,000'/sec, you will see even more penetration.
I tested 200 gn Keith style semi-wadcutters over 3.8 gn of WW231 for only 700'/sec from my snub nosed 38, not looking for expansion but penetration and the load penetrated and exited 6 one gallon milk jugs filled with water (taped together, capped and taped again), all together about 6 feet of water. Well, the dang slug shot through all the jugs and splashed down in my pond about 100 yds away. I use this slug as both a defensive load in my snub nosed 38 as well as a big game load in my 357 for the same purpose, bone busting penetration. I have found that expansion and a 'organ destroying' capability or potential doesn't work on wild game animals or anyone so hopped up on drugs that they do not know they have been shot. Even Whitetail deer shot through the heart with a 30-06 can run up to 100 yds or even more. Some druggie with a knife can still keep coming and stick ya twice in about 1.5 seconds before (possibly) collapsing but shot through with a bullet that busts up their bone structure brings them down. It's a hoot watching you shoot on your U-tube videos although sometimes I wonder what the point is that you are trying to make. If you and your buds want a fun time, sometime, collect some 'uninjured' clay pigeons from the nearest trap or skeet range, set them up at 300-500 yds and have a go at them until they are all busted up too small to see and hit at those distances. Out where you shoot it should make for a lot of dust and fun.