100.0 gr......................2886 fps
102.0 gr......................2923 fps Already topped retumbo load in velocity
104.0 gr......................2969 fps
105.0 gr......................3003 fps
106.0 gr......................3036 fps 100% load density
106.0 gr produced the very first hints of an ejector ring so I stopped there.
Kirby, 100% load density. I have a question but first some base line info. Test rifle 338AX you built with 31" Krieger Barrel 1-10 twist, 300 gr Bergers atop RL-33 using Lapua brass, COAL 3.8915 and near as I can tell about 0.005 off lands, at sea-level (Florida) early morning temp 79 degrees. I took your advice and started load development at 95 gr and worked up. Results as follows:
95 gr.....2627 fps
96 gr.....2645 fps
97 gr.....2687 fps
98 gr.....2722 fps
99 gr.....2752 fps
100 gr...2798 fps
101 gr...2823 fps
102 gr...2856 fps
103 gr...2899 fps
104 gr...2947 fps
primers look good, pockets are tight, bolt lift and extraction effortless and no ejector marks at all. I knew I might be getting close on case capacity so when I loaded with 104 gr I listened carefully for any powder crunching...and there was none. Given results I thought I try 105 gr next and then 106 gr and stop there, however when I loaded case with 105 gr and seated bullet I heard an ever so slight, slight powder crunching, almost as if I removed a half dozen kernels it may not have crunched. So when you say 106gr-100% load density are you getting a slight crunching, how do you know if your at 100% load density and am I already there at 105gr ?
... however when I loaded case with 105 gr and seated bullet I heard an ever so slight, slight powder crunching, almost as if I removed a half dozen kernels it may not have crunched. So when you say 106gr-100% load density are you getting a slight crunching, how do you know if your at 100% load density and am I already there at 105gr ?
For what it's worth, a little trick I learned on this forum was to set your case on a vibratory tumbler to get max case capacity. Here's what I do with a couple cartridges that are right at or near 100% load density.
Charge them one at a time and seat the bullet about 50-75%. Fire up the tumbler and hold the case head down on the corner of the tumbler for about 7 seconds. Fully seat your bullet at this point. Seems to help a lot for me on those cases that are really full.
Not answering for Kirby, but in my experience with compressed loads including RL-33 with my 338 RUM, I will get slight crunching as I approach 98-99% capacity as the bullet is pushing the powder around the sides of the bullet.
After you seated the bullet could you shake the case and hear the powder shake just a little? If so then your just under 100% if not then you're right at it. Either way you are very close to 100%.
No. I didn't experience significant differences in accuracy or POI. Here's group measurements from 3 separate loads - all 3-shot groups at 280yds.
88.5gr / bullet jammed 0.010" = 1.375"
88.5gr / bullet touching lands . = 1.25"
87.6gr / bullets jumped 0.007" = 1.50"
POI was basically identical for all 3 loads. 26" Krieger barrel in a BAT HR action.
I consistently had low ES with these bullets jammed firmly into the lands.