I've been shooting this bullet for a few years in my muzzleloader, and both deer I shot them with died quickly, although I did notice the exit hole wasn't that big. They have proven to be fantastically accurate in multiple guns. This year has been different, and we actually lost deer. The first was a broadside at 45 yards, the buck ran all wobbly about 150 yards, then disappeared into the woods. We tracked for hours that night, it didn't start bleeding for about 50 yards, then it was just a drip here and there until it stopped. We came back the next day, looked some more, but never did find the deer. The next was a doe, quartering towards, about 20 yards. We looked for hours again, but never found a single drop of blood. The next day a buck stepped out, and was shot in nearly the same spot. Again no blood at all, but this time we found the body about 100 yards away. When gutted, it was hit in the left lung, and the bullet zipped right through with what looked like no expansion. Then tonight a doe was shot about 30 yards broadside, and again NO BLOOD. Realize we have had snow on the ground the whole time. Finally we found blood about 75 yards away, and managed to follow the trail easy enough. We have decided to leave it until morning, and fingers crossed we find it. I did not shoot any this year, and now that I think back, the two I've shot with FPB's didn't bleed either. The one was a double lung that died quickly, and the other blew its heart up. Obviously anything less than a perfect shot is BAD news with these. Has anyone else had problems with these expanding? The first buck was shot with 150 grains of 777, if that's not enough velocity to open up, nothing is.