Looks like buck to me, with some pieces at or over the high side of the range. I have gotten buck from four different breakers, but sadly I did not take pictures of everything. These are all the reference pictures I have.
First pic is buck from Reading, second is buck from Kimmel's, third is larger pieces pulled from the Kimmel's buck.
The average dimensions of a given coal size can be different from breaker to breaker, and there is a certain % allowed for under and oversize material. The buck I got from Reading was smaller on average than the buck from Kimmel's, and the buck I got from UAE was smaller yet. The buck I got from Direnzo was right in the middle of the range, and very consistent.
The good news is that the coal you got appears very clean, and free of fines. It should burn fine in the KA-6, but you will probably have to run a longer & more frequent timer cycle in the warm weather than you did with rice.