Yeah, that's because they expand!
Erich:
I said that I carry the 357 short barrel commercial version of this bullet cartridge combination by Speer. I've told this story before on another thread, but I'll hit the highlights here. I was carrying one of my pocket 357s, the M&P 340, I think, and it was loaded with these bullets, but in the factory fodder, which is almost impossible to find anymore.
I had just come home from work and was pulling into my farm, and getting out of my SUV, when my GF's father, who has permission to deer hunt my land, yelled at me that he had wounded a deer and it was headed my way. I later learned that it had jumped just as he pulled the trigger, and he had only damaged a leg. The deer was not dying at that time. Just then it ran past me, in a direction where it was safe to fire. I double tapped the deer, and it dropped within a few feet.
When he dressed out the deer, I asked him to record, to the best of his ability how deep the bullets had penetrated, and to save them for me. I still have them, and will try to take a picture of them to post. You're right: they expand. This was out of a 1 7/8" barrel, and at about 30 yards distance. They penetrated about 14 or 15 inches, and the expansion was just like a picture from a Speer advertisement. IIRC, when I weighed them, they had only lost a couple of grains weight, and had not broken up.
I'm sure that I'm forgetting bits of the story, but I was very impressed with this performance, and it validated what I had read and heard about this fine bullet.
That's why I still carry Speer 135 gr .357 mag ammo in my pocket revolver ( I have a 340 PD, a M&P 340, and a 640-1 Pro Series).
I trust this bullet. I also carry Gold Dots in my .45 Kimber Ultra CDP, when I carry it, and I have them for my .40 Glock, although I don't carry it very much... But like to have a cartridge that I can trust if I ever do. It's what my PD issued in the .40.
Best Regards, Les