I have a H13 choke (.662) and I have the 3.5" straight 7 shells from both lot #300325 and lot #300488. Apparently, EM did not make this change to optimize the load for their choke (or any choke). I got an ~ 15% reduction in my pattern count in 10" at 40' with the new lot number (which I got from Cabela's).
I shot the old lot at 42 degrees and the new lot at 51 degrees . Went though the same cleaning scheme as last time. Wind speed was under 7 mph in both cases.
Then I tested a Jelly Head choke (.660) with the new lot to see if the choke would make a difference (same temp, same day). The average was almost the same. My worst pattern with the Jelly head choke was slightly higher than what I was getting with straight 3.5" 6's (lot #300185) last year .
I also sent EM an email. I only have a few shells left from lot # 300325, so I am afraid to shoot anymore of those this season.