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Old June 9, 2019, 02:38 PM   #1
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Join Date: March 2, 2014
Posts: 6,404
338 Lapua magnum 285 eldm loads

I'm new to this caliber having purchased a savage 110 LRH this winter and have only developed loads with the 230 eldx--which shot very well. I recently came across some scuttlebutt which more or less boiled down to Berger discovered a year or two ago that the 285 gr projectile was the "sweet spot" for the LR 338 LM cartridges; not surprisingly Hornady came out with their own 285 eldm shortly thereafter (or did Hornady discover that first? who knows).

So I just bought some 285 eldms and gave them a go with H1000. I used a ladder of charge weights that more or less followed Hornady's latest manual--starting at 80.8 grs and was going to load all the way up to 89.6 grs per the manual. I usually use their start and end charge weights--but develop 8 different charges and shoot the first four 4 shot charge weights and then the next 4 on a different outing (barrel gets very hot very fast, even though I space the shots 3 minutes or more).

For today's test the first and last charges tested of the first tested group (80.8 and 87.5 grs) yielded pretty good results around .6 MOA at 100 yds.
QL's forecasted velocity for the faster load of 87.5 grs was only 18 fps off from the 4 shot average captured by labradar. However, it was obvious at this charge that pressure was starting to ramp up--nothing beyond a bit of cratering in the pin strike on the primer, but the bolt was also getting a bit stiffer to unlock. QL says even at this load I'm reaching 61,500 psi--but the rest of the charges in Hornady's manual looks like they top out at almost 68,000 psi in my 26" barrel--and only for a gain of 50 fps.

My thinking is forget about the rest of the ladder and call it a day at 87.5 grs--maybe even back it down a bit and see if I can find an equally good group. I'm not worried so much about a kaboom as stressing the bore. I'm glad I cross-checked with QL and my labradar results.

I'm new to loading this cartridge--any advice?

PS: If you have a sharp eye--you'll notice the kinetic energy figures are WAY off--that's because I accidentally re-used the 190 gr projectile weight from the last ladder I tested. Hate it when that happens. : )
Attached Images
File Type: jpg 338 lapua 285 eldm 80.8 H1000.jpg (170.0 KB, 161 views)
File Type: jpg 338 lapua 285 eldm 87.5 H1000.jpg (116.1 KB, 160 views)
File Type: jpg 338 lapua 285 eldm 87.5 H1000 labradar.jpg (64.0 KB, 161 views)
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Last edited by stagpanther; June 9, 2019 at 02:47 PM.
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