I had the same experience. Surprisingly accurate but no expansion to speak of.
That was a real bummer to find out. I saw the early reviews and was pretty excited based on the reports, but also a little skeptical. My shelf is littered with all manner of fancypants expanding pellets I've accumulated over the years. Most won't confidently hit the kill zone of small critters past 30 yards. Got to give them a fair shake though so I ordered a couple of tins back in June. Imagine my surprise when the very first group at 43 yards looked like this:
Could it be? An expanding pellet that rivals the accuracy of a dome? I was excited to get out and try them on small game...so I promptly forgot about them ;D What can I say, summers are busy with 6 kids ranging 2-14.
Fast forward to December when a forum topic reminded me I needed to try them. When I got home from work New Year's eve, I lit the target in the back yard with a flashlight and fine-tuned the zero.
I set my alarm for 5:00am. At 3:30am, I woke up and couldn't go back to sleep so I got up and made some coffee and readied everything and headed out at first light. It was a cool 33°F and I figured that would kick these eastern grays in the pants to go out and forage.
It wasn't long before I saw the first one. It became the recipient of a brain shot...the Hades went exactly where asked and the squirrel did the familiar catfish dance for about 15 seconds before coming to rest. With the DAR sending them out at about 900fps, that's a confident passthrough and I really wanted to see how much it will expand if given the opportunity so I decided if I got another shot, it would be to the vitals.
Turns out there wasn't a lot of activity but eventually I spotted another. He presented me with a nice shallow quartering angle so I carefully aimed to put it between his neck and front shoulder, putting the path through the heart and lung area and diagonally for almost the full length of the body.
The impact sounded like a fast ball popping the catcher's mit. The squirrel tumbled and managed to run about 7 yards before running out of steam. Tough critters. On retreiving him, I could feel the pellet under the hide next to the spine. In this photo, the tape measure shows the approximate path it took:
Using Chairgun, I'm estimating it had about 21fpe on arrival. On inspecting the pellet, there was no evidence that any substantial bone was encountered, meaning the full energy dump was dissipated in about 4.5" of hide, muscle, and soft tissue.
Unfortunately it hardly expanded at all. Here it is in the jaws of the calipers next to an unfired one:
I have to say I'm underwhelmed. Accuracy is very good so they'll definitely get the job done but this limited experience hasn't convinced me they are worth the cost premium over the domes.