I'm doing my best to understand it myself,
I tried multiple rolls of tri-x, from the same batch, exposed under similar lighting conditions. Agitated them in my usual way. (continuous for 30 seconds, then 10 seconds each minute at the bottom half of the minute.)
D-76 was 1 to 1, for the listed development time, HC-110 was dilution B for 6 minutes, (I disagree with the 3-1/2 minute listed time. )
D-76 negs came out underdeveloped and thin, the only way I found that I can get decent negs from Tri-X in D-76 is to agitate 10 seconds every 30 seconds and develop at N+2 or N+3. And then they are still not as well developed as they are using HC-110 Dillution B for 6 minutes.
I have spend quite a few rolls of film trying to get D-76 to work for me, and I have used it very successfully tank developing quite a bit of Ilford HP-5+ 4X5.
EDIT: I am also now rating Tri-X (Expired) at ISO 200 and Fresh at ISO 320. I'm going to see if that helps.
Originally Posted by Roger Cole