Years ago I did a head to head comparison between TAC & H-335, in the 223 cartridge. One of the main areas was cleanliness. Was it scientific, no. Like often is the case, lower pressure loadings can be a little ‘dirtier’. Did I give unfair advantage to TAC with higher pressure loads? I tried not to. Did I have ‘expectation bias’, maybe.
In my test I fired the same number of H-335 rounds, observed, cleaned, then the same with TAC. In my casual observation it showed TAC being cleaner, less action residue.
One may say, so what. This came up during a dog town trip to SD. An AR action became gummed up after 100’s of rounds fired. Now I mostly use the TAC loads & often do a field cleaning after 2 days.