7mm WSM, 180's and Re17

Discussion in 'Reloading' started by Bill308, Oct 20, 2013.

  1. Bill308

    Bill308 Well-Known Member

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    I'm having a difficult time finding reloading data for 7mm WSM flinging 180 grainers down range. Either SMK's or Bergers and even Noslers new ABLR 175. Does anyone have any idea where to start with some loads? I've been using Reloder 17 with 200 grainers in my 300 WSM and it has worked beautifully. Thank you

    Bill
     
  2. stomp442

    stomp442 Well-Known Member

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    I would use the 175 data. Start low and work up.
     
  3. Bill308

    Bill308 Well-Known Member

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    Neither Nosler nor Alliant has load info for 175's. Do you mind pointing me in the right direction, thank you.
     
  4. MontanaRifleman

    MontanaRifleman Well-Known Member

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    If you use the google search in the upper right of the page and type in "7WSM RL17" you'll get a lot of good info.

    I have used RL17 in the 7 RM with 160 AB's and max'd with about 88% capacity. Velocity was very good but Retumbo was only 50 fps behind with 100% capacity and I like full cases.

    The 7 WSM is very close in capacity to the 7 RM and a 180 bullet is going to be on the heavy side for a powder like RL17 in that case.
     
  5. cummin_un_glued

    cummin_un_glued Well-Known Member

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    if you like the RL powders then RL25 would be a closer match I think. it is slower than RL17. H1000 would be even slower then the RL25.

    seems like I remember there being some RL33 data on here for the 7RM with a 175gr that shows a max of 75gr that might be the best match for case capacity. I am running the 180 bergers out of my 7mmx300win with 80gr of RL33 and it gives me 99% fill and 3200fps with less pressure then 75gr of h1000 which only yields 3150fps.

    just giving you some ideas
     
  6. Max Heat

    Max Heat Well-Known Member

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    Whoa, I have evolved into a huge fan of the Reloader series powders. But I have never used 17 in anything 7RM or larger. Unless you have a relatively short barrel, or lightest-for-cal bullets, my thought is that it is probably a tad too fast. But conversely, 25 might be a bit too slow for how much capacity the case has.

    My point is that jumping from 17, straight up to 25, while skipping right over 19 and 22, is like going from 1 extreme to the other, skipping right over the "sweet" area. Take it or leave it, but MY advice would be to go up 1 step at a time. But I think that the OP will find no need to go with any higher than 19.

    I can't speak for WSM, but I have found that 75gr (full case) of 19 yields optimal performance out of the 7RM, using mid-weight bullets, out of a 26" barrel. That IS a max load, so don't go there if your headspace isn't tight.

    I'd like to take advantage of this opportunity to challenge anyone out there to show me a powder that can outperform 19 in a 26" 7RM.
     
  7. MontanaRifleman

    MontanaRifleman Well-Known Member

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    I have found 17 likes heavy for cal bullets as long as the cartridge isn't too overbore. I.e. It shoots 210 bullets out of a 300 WSM very well.

    I do think it's on the fast side for heavies out of the 7 mags, which are a little more overbore than the 300 WSM, but it shoots the lighter ones very well from what I've read.

    Before H1000 and Retumbo came out, the 4831 powders were very popular in the 7 RM and IMR 4831 was my go to powder for 160's. But now, H1000 and Retumbo (in the same category as RL25) have shown very good results with heavier bullets (160 and up) in the 7 RM which is just slighter larger in capacity than the 7 WSM.

    I would skip 19, 4831 and go right to H1000 and/or Retumbo, especially with a 180 bullet.
     
  8. Bill308

    Bill308 Well-Known Member

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    I already have the powder (RE17 or RL17) so wanted to try it out with 7mm WSM. I realize other powders have shown great potential with the 7 WSM and heavy bullets, but am surprised that no one has really played around with RE17. As I understand it, RL17 is different from all the other Reloder powders in that it has inhibitor's blended in with the powder that maximize its potential for WSM type cases.

    Would anyone have played with RL 17 in the .284 Win until Jim Hardy did his tests?

    This may be a moot effort, but thought it couldn't hurt to ask.

    Thanks for the search info MontanaRifleman, I will check that out...
     
  9. MontanaRifleman

    MontanaRifleman Well-Known Member

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    Bill,

    RL17 woks well in the WSM's but the 7mmWSM is different than the 300 WSM in it's volume to bore ratio, so 17 is going to have different performance characteristics in those 2 cartridges. In the 300 WSM, it does very well with 165 to 215 bullets. In the 7 WSM you're probably going to find the best results with 150 gr and less. The 284 Win is a smaller case and has a closer volume to bore ratio to the 300 WSM and is an ideal case for RL17.

    You can try it with 180's in the WSM, but you're going to find it's on the slow side burn rate wise and will leave you with a lot of empty case space. If you can't find a good starting load, give Alliant a call. Otherwise, I would probably start with about 80% seated bullet case capacity and work up.
     
  10. Bill308

    Bill308 Well-Known Member

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    Thank you Mark for that detailed reply, that helps me a lot. I had always thought it had to do with a longer bullet surface to barrel contact that played a role in pressure, but this volume to bore ratio makes sense too. Sad that I have been reloading for 24 years but have never fully understood this. I've read a lot on this forum and it has sure helped me grow in knowledge.
     
  11. MontanaRifleman

    MontanaRifleman Well-Known Member

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    Bullet bearing surface does play a small role as do some other considerations like throat design, but for the most part volume to bore ratio is the key determiner.
     
  12. Bill308

    Bill308 Well-Known Member

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    Help me out here, so if 7mm WSM has 81 grains capacity with a bore of .284, would I divide 81/.284 = 285.2 and then do the same for other rounds and this should give me a better idea for powders that could be shared between different rounds?
     
  13. MontanaRifleman

    MontanaRifleman Well-Known Member

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    What I do is find the bore diameter area - radius squared times pi

    .284" x .5 = .142"

    .142 x .142 = .020164"

    .020164" x 3.14 (pi) = .0633 square inches = bore area


    Then I find the H2O volume which I get from AmmoGuide which is 79.7 for the 7 WSM

    I divide 79.7 by .0633 = 1258

    The water volume in Ammoguide includes neck space (I think). Ideally, you want to compare volume of powder space (in water volume, not powder volume) but it gets you close enough for a ballpark idea. This is also a good method for determining potential barrel life.

    I have been looking at RL33 a lot and 1258 would be borderline good case for for RL33 with heavy bullets. A higher ratio might be better but 1258 could produce good results with heavy bullets.
     
  14. cummin_un_glued

    cummin_un_glued Well-Known Member

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    I only shoot heavy for caliber bullets out of all of my guns so i'm used to the pressures that they create. Now I do agree that the RL25 might not fill the case as well as the others. I would probably swing toward the H1000 if it were me but the OP seems to like RL so that's the next closest thing.