Not much primer choices for 338lm I don't think.... I use 215M's. As far as brass prep, we are talking about lapua brass with everything done (and annealing every reload) except neck turning.
I weight charges with a chargemaster and confirm on the scott parker tuned M5 scale.
With these bad SD numbers, its not that there is one 'flier' FPS wise, but they are spread it pretty evenly.
I'm not sure what to try next. I'm thinking I might try loading up a couple with my friends retumb and primers, and then also try loading with h1000.
Hey Timelinex,
Not sure if any of following may make sense to your situation.
I know you previously mentioned you double check your RCBS with second scale.
I found my RCBS CM does not throw consistent charges. At least for me.
In example below my CM said charge was 24.7 but yet my Sarorius AY 123 says other, 24.60. Granted this is a .223 powder charge but still 0.1 grains off. So my thought is IF my .338 LM powder charge even varies from 92.05 to 92.15 that one grain spread just be cause for high SD??? Maybe???
* I went with above setup when I was experiencing high ES' two years ago. Once I went this route, along with other changes made my ES dropped significantly.
* IF I get real anal and stick with 92.10 and 92.12 powder charges my SD's drop to 8 to 11 and this is without neck turned brass.
* When I sort my hand loads by ease of bullet seating SD decreases. <<< Does this make sense?
* maybe various neck tension is helping in SD issue?
I am just trying to throw thoughts out at you to see if maybe something throws a spark.
Another thought I just had. Have you considered purchasing another box of 100 Lapua Brass? Probably a long shot, I am wondering if annealing brass after each firing maybe causing inconsistent neck tension??? I am wondering what your results would be if you broke a new lot of 100 into say 5 lots of 20 and went from there. Not sure if this makes any sense to try.
I spoke with another guy on here who had his custom .338 LM built by same Gun Builder as I and he wound up changing from Retumbo to H1000 and his groups to one mile tightened up. He has a thread on here displaying a 5 shot 8 inch group at a mile. I do not know if he had SD or ES issues. I do know he had VERTICAL issues with Retumbo at 1000 yards. H1000 rectified his VERTICAl issue.
Have you tested your scale with following or similar?
Example:
1. Throw charge via CM (92.1)
2. Double check above on your Scott Parker tuned M5 << I assume will confirm
Q1: How many kernels do you have to remove from SP scale to reach 92.0 grains from 92.1?
Q2: How many kernels do you have to remove from SP scale to reach 92.2 grains from 92.1
Q3: What does your SP scale read when you take a confirmed 92.1 charge MINUS two kernels?
Q4: What does your SP scale read when you take a confirmed 92.1 charge ADD two kernels?
Not sure if you follow my thought and where I am going with above.
Safe shooting
