Several years ago, my brother and I got started in reloading. I started out trying the Hornady SST 150 grain bullet. I got decent groupings of 2 inches or less, but there would be no constancy with the shots (same powder, primer, etc.. in each round). I then shot a deer with on of the rounds. While inspecting the deer's body, inside and out, I noticed that it appeared the bullet was "tumbiling" (the wound channel was not neat and "uniformed" as one would expect). To test my theory, I set out to try and "catch" a .270 bullet that had been fired. I used 7 full water jugs set up at 100 yards and I caught my bullet on the first shot. What I noticed was that the SST had separated from its copper jacket (never found) and instead of a nice mushroom that starts at the head and rolls down; I got what I consider a sideways mushroom (picture attached). I still have those SSTs , but am only shooting them at targets now just to use them up. I have since switched over the the 160 grain Partition. Now I am getting 1 inch groups with consistency. I took two deer with them last year (both dropped in their tracks, where I had to trail the SST shot deer, and with nice even wound channels). I have tried the lower grain bullets, but my Browning A-bolt just absolutely LOVES these 160 grain rounds. I have tried to "catch" a Partition, but I need more water jugs (7 just ain't enough, LOL)