I burned a little bit of powder today with Azshooter, and luckily I was able to use his chronograph. I shot both Us 869 and Retumbo, the results were as follows:
80.5 gr US 869 averaged 2985, with an ES of only 5. (this is only two shots, the chrongraph did not register the first shot).
81 gr US 869 averaged 2989, ES of 20
81.5 gr US 869 averaged 3018, ES of 25
82 gr US 869 averaged 3051, with pressure starting to show, ES 33.
Retumbo.
69 Gr. Retumbo Averaged 2871, ES 27. Accurate load, two were in the same hole.
70 Gr. Retumbo Averaged 2910 ES 40, with good accuracy potential (triangle about at about an inch).
71 Gr. Retumbo Averaged (skipped 71 grains)
72 Gr. Retumbo Averaged 3003, ES 38 with good accuracy potential (triangle about at about an inch).
The first group was shot at about 80*, and final was shot up about 90*.
I like the accuracy potential of Retumbo, although those ES' are fairly high for shooting 700+. US 869 is definitely in the mix, showing accuracy potential, with good speed, although given the choice, I'd rather burn 10 grains less for similar speed, ES and accuracy.