As promised, we went to the range with the 8mm Mauser. Over the chronograph, the lowest load ran 1470 fps +/- 15. The fastest load ran 1530 fps +/- 13. Group size was better. Maybe not a 1 inch group yet, but far improved over the pulled bullet loads.
The big downside. At that velocity, the replacement sights do not have enough adjustment to get the hits centered on a target at 100 yds. With sights at upper maximum travel, bullets were impacting 8 to 9 inches below aiming point. Velocity will have to be increased or some other sight will have to be mounted.
The upsides. There's plenty of room in the load data to speed up the bullets, certainly enough to get back inside the adjustment range of the sights. The bore is clean, no lead being deposited, so moving up in velocity is a realistic decision. Hoping to gain 200 fps and then start working again on accuracy.
Going to load this week, keeping everything same except the powder. Range again next weekend.