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Old June 9, 2019, 02:38 PM   #1
stagpanther
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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, 135 views)
File Type: jpg 338 lapua 285 eldm 87.5 H1000.jpg (116.1 KB, 136 views)
File Type: jpg 338 lapua 285 eldm 87.5 H1000 labradar.jpg (64.0 KB, 136 views)
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Last edited by stagpanther; June 9, 2019 at 02:47 PM.
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Old June 11, 2019, 09:33 AM   #2
Howland
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I'm also loading .338LM using 285 ELD-M and H1000 in an RPR using Lapua brass and 215M.

OCW results showed best accuracy at 79gr., almost indistinguishable point of impact change at 84, 85 & 86 gr. and very low velocity change between 88 & 89 gr.

I did seating depth testing at 79, 85 & 89 gr. but accuracy was still best at 79. I kept trying to find a node at higher velocity but it just might not be there. I've got two groups below .6 MOA but it seems like low 6's may be it. You're fortunate to get that at 2,733 w/ good ES and SD.

I used to be of the opinion that I load for the most accurate groups and if I need more velocity or energy it means I'm getting a new rifle. I might just have to settle for what it gives me this time. If I had cratered primers and stiff bolt lift, I would back off a bit and stop.
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Old June 11, 2019, 10:17 AM   #3
stagpanther
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Quote:
'm also loading .338LM using 285 ELD-M and H1000 in an RPR using Lapua brass and 215M.

OCW results showed best accuracy at 79gr., almost indistinguishable point of impact change at 84, 85 & 86 gr. and very low velocity change between 88 & 89 gr.

I did seating depth testing at 79, 85 & 89 gr. but accuracy was still best at 79. I kept trying to find a node at higher velocity but it just might not be there. I've got two groups below .6 MOA but it seems like low 6's may be it. You're fortunate to get that at 2,733 w/ good ES and SD.

I used to be of the opinion that I load for the most accurate groups and if I need more velocity or energy it means I'm getting a new rifle. I might just have to settle for what it gives me this time. If I had cratered primers and stiff bolt lift, I would back off a bit and stop.
Your results don't surprise me--I also experienced a great load at around 80 grs with excellent numbers--but it's a "low end" load but I totally agree with what you say--unless you're shooting way long--who cares. I also experienced the same thing you did with "point of diminishing returns" with incremental increases in charges towards the top end.

Unclenick--who I've come to respect as having some of the best insightful comments on any forum anywhere--recently commented on the relation of Quick Load projections and the factors in the reloading process that might effect projections "vs reality." He observed the important role that the projectile's position in the Freebore relative to the lands--can have a impact on the resulting start pressure within the chamber upon cartridge firing. My limited experience with seating depths in the 338 Lapua Magnum brought this point out perfectly as I was seeing noticeable increases in velocity for the same charge loaded closer (but still not engaging) the lands. Just as he said, I had to "jigger" the weighting factor to add back a good start pressure figure into QL's projection.

Another thing I've observed about hornady's eld's in general across all calibers--they seem to be more forgiving of long jump to lands than most other bullet form factors I have used; or maybe another way to look at it is that they don't necessarily need to be very close to the lands to optimize performance. I've often wondered why that is; and it's no doubt fodder for endless conjecture on many forums as it gets into all kinds of technical esoterica (most of which I don't have a clue what they are talking about LOL). My personal "hypothesis" is that hornady's design simply is better at self-centering in the freebore than most other designs. That's pure "pie in the sky" conjecture on my part, though.
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Last edited by stagpanther; June 11, 2019 at 10:29 AM.
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Old June 11, 2019, 04:35 PM   #4
Howland
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Loaded to mag length gives me about .080" jump to the lands so that is where seating depth testing started. I don't want to single feed. 0.090" jump got the same group size but they opened up as I moved back so 0.090" is it.

I am going to try to reach out for distance but the furthest I've had it yet is 500 yards. Even though velocity would help, keeping the tightest groups I can get will help more. I'll just need more clicks.

I had also heard that the ELD profiles are forgiving of jump. That and knowing they shot tight groups in another rifle I am familiar with was why I started with them.

As to the point of diminishing returns at the upper end, I would have expected the opposite to be true, radical increases in both velocity and pressure as you approach max loads. Just the other day I came across someone who has done extensive pressure testing and I asked his opinion on that hypothesis. He also said that he observed lower velocity increases per unit of powder when approaching maximum loads even though the pressure was beginning to spike. I'm glad I've made it a point to stay away from that zone.

FWIW, my brother worked up a load with Retumbo and also found his accuracy node at a relatively low charge and velocity and he too went right up to book maximum.
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Old June 11, 2019, 05:20 PM   #5
stagpanther
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I'm seeing no pressure signs--but then again I use Lapua cases which are very strong. I used Hornady's load data from their latest manual--but I reached a velocity very close to their top load of 89.6 grs' velocity of 2750 fps using only 87.7 grs which is a bit under even their next-to-top load. I was a bit stumped by this--but QL agrees with my test results for it's projected velocities, so I stopped at 87.7. I too load to mag length, but maybe savage's is a bit longer than the RPR's?
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