If I posted these before, please to forgive.
.219 Zipper fired in Marlin 336SC (1959) 20" barrel. Neither load chronographed. These are not recommended loads. I am just reporting what worked in my rifle at 100 yards in 10-15 mph winds from the left front:
28 grains IMR4064/52 grain Sierra HPBT/WLR primer/W-W 30/30 formed brass/single loaded at 2.46" OAL: 3 at .402"
26 grains IMR4064/52 grain Sierra HPBT/WLR primer/W-W 30/30 formed brass/single loaded at 2.47" OAL: 5 at .75" (one pulled-4 at .60").