Loading 300 Bergers with Retumbo in Lapua

Discussion in 'Reloading Forum (All Calibers)' started by calgarycanada, Feb 10, 2016.

  1. calgarycanada

    calgarycanada

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    Hello guys
    trying to develop a load for 338 Lapua. I have load info from Berger, Hogdon and Quickload.

    Somehow Berger is getting 2680 fps with 89 ish(don't remember exact number) of Retumbo in 26" barrel if I remember correctly.
    Hogdon is getting 2654 from 94 grains in 24" barrel.
    And Quickload when tailored to my case capacity of 117 grains and OAL of 3.9+ is telling me I can only get little over 2700 fps in my 30" barrel.

    Velocity part doesn't bother me much but the part that bugs me is according to Quickload Retumbo is 100% burnt in under 20" barrel length. So that means Retumbo is too fast for my roomy chamber??
    Apparently RL33 and VV 570 are better fit in my case but I'm concerned about temperature sensitivity of those two.
    I understand Quickload is not exactly accurate but it can't be that far off? Or can it be?
    Experts, if you were in my boots, which powder would you pick??
    Thanks in advance.
     
  2. dkhunt14

    dkhunt14

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    RE33 shoots great in my 338 Lapua IMP. Capable of 3150 plus. I am running it 2993 with 104 grains and a Berger 300. In a 338 Ultra it got 3000 with a Berger also. It shot great in both guns with 4 to 6 inch 5 shot groups at 1000 yards. Matt
     
  3. barefooter56

    barefooter56

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    calgarycanada,
    N-570 is one to VhitaVouris extreme powders and should be temperature insensitive. Now, I will say that its been my experience with an N-500 series powder (N550) that as the powder gets older it gets hotter. So drop back a grain and work back up every year to be safe if your load is on the high side. RE-33 ...I would suggest going to the ALLIANT website and calling one of their powder techs.
     
  4. calgarycanada

    calgarycanada

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    Thanks for the info
     
  5. double g

    double g

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    Retumbo burns itself up to fast and works better in shorter barrels and smaller cases.
    DG
     
  6. calgarycanada

    calgarycanada

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    I guess Quickload is correct. In my chamber Quickload predicts 100% burn in under 20" of barrel.
     
  7. calgarycanada

    calgarycanada

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    Need more help guys,
    I was able to get RL33. I ran some rounds through to find out max load for my gun. I started at 98 grains as Quickload predicted I could go up to 105 grains. I started measuring velocity with Caldwell chronograph. At 99.5 grains I got 2848, 2850, 2848 fps for 3 rounds. Went upto 100.5 2940, 2954, 2942 fps, no pressure signs. Finally I tried 101.5 grains chrono 2973, 2977, 3000 fps, minor ejector swipe.
    With my OAL of 3.922" and capacity of 117.5 grains Quickload is predicting over 100 fps less then chrony, i.e. 2822 fps with 100.5 grains . One these devices is wrong of course. I will confirm velocity based on my drop numbers when weather allows but for now, Question for those who run 338 lapua with RL33 and Berger 300s, Just wanna know how much RL 33 you use and what velocities do you get?
    Thanks in advance
     
  8. 338 dude

    338 dude Silver $$ Contributor

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    I use n-570 it is the best in my rifle
     
  9. LA50SHOOTER

    LA50SHOOTER Silver $$ Contributor

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    I run 97.0 gr. of RL33 in New Lapua Brass with a 300 gr. Berger OTM Hyb. as a fire-form load in a 28" barrel that is chambered in an Improved version which yields approx. 2750 fps. - COAL is 3.950 (About -.003 off the lands)
    In a fire-formed piece of brass (Lapua) I've worked up to 106.0 gr. of RL-33 in the same 28" barrel for a M.V. of 2965 fps & good accuracy.

    Another V/V powder you may want to consider is 24N21 which is just a "tad" slower than N-570 and is very close (but NOT the same) to RL-33.
    I have 3 different rifles chambered in 338 Lapua Imp. with 28", 30" & 34" barrels, So far Reloder 33 has yielded the best Accuracy and Highest Velocities without adverse pressure signs at all in all 3.
    IMO it the "go to" powder for this cartridge and some others as well.

    - Ron -
     
    dkhunt14 likes this.
  10. Wildcat455

    Wildcat455

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    Feb 27, 2018
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    Savage 110 FCP-HS
    9 twist 26" barrel

    99.5 gr RL 33
    Hornady case
    300 gr Berger EH
    2800 FPS
     
  11. Sniper338

    Sniper338

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    Im 98.5gr re33 and 300 berger lapua brass in a 30 inch kreiger.
     

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