New 338 NM Build and Load Work Up Advice

Discussion in 'Reloading Forum (All Calibers)' started by JW74, Aug 6, 2019.

  1. JW74

    JW74

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    I just had a 338 Norma magnum built and am in the early phases of my load work for it. If others here that have loaded for the 338 NM could give some feedback it would be greatly appreciated.

    The rifle is built on a Defiance Deviant action with a Bartlien barrel (27” heavy varmint contour @ 1:9.3” twist).

    I went with 300 grain Berger bullets to start and H1000 powder as this seems to be a very common combo in the 87-88 grain range at 2700+ fps. I started very conservatively, and the loads and velocities are as follows:

    300 grain Berger Hybrid OTM
    H1000
    Fed 215M
    New un-fired Norma brass
    2.836” to ogive (0.018” jump)

    1) 81.0 gn @ 2584 fps
    2) 81.5 gn @ 2595 fps
    3) 81.8 gn @ 2618 fps
    New Lot of powder used (velocities dropped)
    4) 82.1 gn 2540 fps
    5) 82.5 gn 2590 fps
    6) 82.8 gn @ 2585 fps
    7) 83.1 gn @ 2610 fps
    8) 83.4 gn @ 2620 fps
    9) 83.7 gn @ 2627 fps
    10) 84.1 gn @ 2630 fps

    This was over a couple of range sessions. I am still ~4 grains and 100 fps below what most people are getting with H1000 and I am starting to see signs of pressure with flatish looking primers, no cratering of the primers though and no stiff bolt lift yet. All of these groups were close to 1/2” at 100 yards with SD’s from 4-12. I still have a little room to go up in charge but don’t think I will get close to 87-88 grains without high pressure. I am wondering if I may have a tight barrel and that is why I am seeing pressure earlier than most?

    I also tried the same loads but substituted Reloader 33 for H1000.

    300 grain Berger Hybrid OTM
    Reloader 33
    Fed 215M
    New un-fired Norma brass
    2.836” to ogive (0.018” jump)

    Those loads were:

    1) 91.0 gn 2559 fps
    2) 91.5 gn 2574 fps
    3) 92.0 gn @ 2601 fps
    4) 92.5 gn @ 2610 fps
    5) 93.0 gn @ 2642 fps

    The Reloader 33 produced these velocities with no real signs of pressure but the groups were not as promising as with H1000 and the SD’s averaged higher at 15-20.

    Thanks for any feedback or advice on these loads and further load development as it is greatly appreciated.
     
  2. boltfluter

    boltfluter

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    Great cartridge and a generally very accurate . Buddy uses H1000 in his for best results. Your barrel will probably pick up some speed as it gets broken in. :D:D

    Paul
     
  3. JW74

    JW74

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    Thanks Paul! Is your friend able to get up into the mid 2700's+ without pressure? I really want H1000 to workout for me as the groups have been fantastic early in my load development process.
     
    Last edited: Aug 7, 2019
  4. Kurz

    Kurz

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    The data I've worked with tells me a couple of things right off the bat:

    Re-33 is a tad slow for this combination.

    The 300 grain Elite Hunter and other 300 grain .338 bullets are overweight for cartridges in the 100 grain capacity class and seating them out does not make a difference. These bullets can actually use the bigger cases to achieve what they are capable of, not these loping velocities that folks find acceptable due to peer pressure.;) I achieve much better results from using the 250 grain Match and VLD hunting bullets than from any one of the 300 grain bullets. The 250 grain bullets are a perfect match for the 100 grain capacity cases.

    My .338 Norma Mags are:
    32" Match
    28" Hunting
    27" Hunting

    You can get to the 2,700 fps level with the 300 grain using H-1000.

    Also VVN-570 will go past that to the mid-2,700 fps. Same for Retumbo and Norma 217.

    The 245 Lehigh Match can get to the mid-2,959 fps level with re-25, H-1000, VVN-560.

    The 250 grain Elite Hunter does the same. There have been a couple of excursion nearing the 3,000 fps level but the dragon sleeps here!:eek:;)
     
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  5. JW74

    JW74

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    Kurz,

    Thanks for the info! I do plan to run some lighter loads, 300's is what I started with as that seems to be what most were shooting when I was researching 338 NM load data. Have you had any luck with Reloader 33,26, etc with your rifles?
     
  6. Kurz

    Kurz

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    This is the information as I wrote it above your post. If you want to shoot the 300 grain then use VVN-570. If you switch to the lighter and better balanced 250 grain, then you have a choice of Re-25, H-1000 and VVN-560.

    I shoot the 245 grain Lehigh Match, 250 grain Elite Hunter and the 255.5 Warner Flat Line.
     
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  7. JW74

    JW74

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    I was at work and I read through the top part of your first post too fast and blazed past your comment about RE 33. My bad! lol. Thanks again for the info, it helps a lot!
     
  8. Rdlningcltchdmpr

    Rdlningcltchdmpr Gold $$ Contributor

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    Try( LRT) powder and us869 . they are great as you get a full case ussually
     
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  9. mchees1

    mchees1 Silver $$ Contributor

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    I have a 338 Norma with a 28" Hart barrel with 1:10 twist and Stiller TAC 338 action. My best load is 81.8 grains of RL-22 and Lapua Scenar 300 grain bullets. I use Norma brass. OAL is 3.554" which gives me 0.014 jump. Velocity is right at 2777 fps with 8.1 SD. Shoots pretty consistent .3 to .4 moa at 200m. Using CCI 250 large rifle magnum primers.
     
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  10. boltfluter

    boltfluter

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    JW,

    He had no problem getting to 2750 fps with H1000. Good luck and carry on!! :D:D

    Paul
     
  11. JW74

    JW74

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    Thanks mchees1! I have some RL 22 and will give it a try. You are getting great SD's, velocity and accuracy with that load!
     
  12. mchees1

    mchees1 Silver $$ Contributor

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    Hope it works as good for you as it does for me! I also shoot with a direct thread suppressor. Haven't tried it without the suppressor to see if there is much difference.
     

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