In an effort to find a hunting load for my recoil-sensitive 12 y/o daugher, I loaded up some 71 gr. Hammer Sledge Hammers over 34 grs. of H4895 (Winchester brass, CCI LRM primers). My goal based on an online load calculator was to get to ~3,000 fps (starting load data shows 3,286 at 36.0 grs). At the range the chrono showed velocities from 1,990 to 2,425 fps (extremely wide spread) and nowhere near the velocity that the calculator had suggested. Surprisingly, accuracy at 100 yards was good.
Ordinarily I would doubt the chrony but I shot some 6.5CM through it afterwards and it read roughly expected velocities w/ minimal velocity deviation.
Based on that experience I have a few questions:
1) Working up from the 60% load for 4895, I realize that there will be a lot of air space in the case. Could the variability of how the powder sits inside the case create that much velocity variance? 34 hrs. isn't that far off the 36 gr. starting load, so that seems odd.
2) I seated the bullets out fairly far. I don't have the measured length on hand, but the first convolution on the bullet was outside the case mouth. Could that possibly cause the reduction/variability in velocity? I can't see how that would be the case.
3) Does anyone have any alternate powder recommendations for a light .243 load? The listed min velocity for.most powders is quite a bit faster than I desire.
Ordinarily I would doubt the chrony but I shot some 6.5CM through it afterwards and it read roughly expected velocities w/ minimal velocity deviation.
Based on that experience I have a few questions:
1) Working up from the 60% load for 4895, I realize that there will be a lot of air space in the case. Could the variability of how the powder sits inside the case create that much velocity variance? 34 hrs. isn't that far off the 36 gr. starting load, so that seems odd.
2) I seated the bullets out fairly far. I don't have the measured length on hand, but the first convolution on the bullet was outside the case mouth. Could that possibly cause the reduction/variability in velocity? I can't see how that would be the case.
3) Does anyone have any alternate powder recommendations for a light .243 load? The listed min velocity for.most powders is quite a bit faster than I desire.