Bullet weights vs. Powder burn rates

Discussion in 'Reloading' started by meatyrem, Sep 10, 2011.

  1. meatyrem

    meatyrem Well-Known Member

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    There have been many on here talking about the "right" burn rates with a given bullet weight. With the 280 rem I was wanting to hear from those that know a little somthing about this. 140 gr-150gr-160gr and what type of burn rates are known to give good results with these bullets. Are there certain bullets/weights that work better with certain powders?
     
  2. boomtube

    boomtube Well-Known Member

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    Burn rates are interesting to talk about in a general way but you've paid good money for a loading manual. It's easy to see what powders work best for each cartridge and bullet weight in those data tables and that's as precise as we can make it.
     
  3. diriel

    diriel Well-Known Member

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    4350 and 4831

    Gary
     
  4. backwoods83

    backwoods83 Well-Known Member

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    In all actuality the reloading manuals are more like guide lines, they show the best case senario with a given firearm or barrel length. In reality faster powders tend to work better in short barrels and slower powder tend to gain more velocity in long barrels, its all about the flash rate and distance. Do a search on internal ballistics( what goes on from when the primer is struck until the bullet has passed the muzzle blast).
     
  5. meatyrem

    meatyrem Well-Known Member

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    So in a sense like, 4350 with a 22" and 4831 with a 24" and h-1000 with a 26"?
    Both of my 280's have 24" barrels. I figured starting with h-4831sc. I also have h-1000 and I see a lot of loads with that powder for the 270. So is that kinda like along the same lines?
     
  6. backwoods83

    backwoods83 Well-Known Member

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    140 Imr4350 or RE17, 150 H4831sc, 160 Imr7828, H1000 is better in a 26" barrel 270 with 150s, to slow for a 280 imo but does good in a 26"+ 7mm rem mag.
     
  7. boomtube

    boomtube Well-Known Member

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    "In reality faster powders tend to work better in short barrels and slower powder tend to gain more velocity in long barrels, "

    Not really but that's a common misconception.

    First, peak chamber pressure occurs in less than 4" of bullet travel so that part doesn't matter no matter what powder is used.

    Second, any powder that will produce the max speed in a long barrel will do the same if you cut the same barrel back. (Not the same speed of course but it will still be the fastest powder.) Meaning it's the time:pressure curve that matters for what will be fastest, not the burn rate:barrel length that will determine the most efficent powder for any given load in a given rifle.
     
  8. backwoods83

    backwoods83 Well-Known Member

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    Well once again I'm sorry I'm a dumb a$$, I thought peak pressure began when the bullets bearing surface fully engaged the lands, usually less than am inch. And 4350 will have just as long of a flame travel as some slow a$$ H1000, hey I don't know, just another ignorant redneck!
     
  9. rscott5028

    rscott5028 Well-Known Member

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    Quick Load is a software program that allows you to simulate the affects of pressure curves, velocity, changing components, barrel length, etc.

    It's no substitute for safe loading practices. But, it'll help you spot things that aren't going to work and identify some possibilities that might be worthy of actual load workup.

    I played with the demo. But, I haven't sprung for the full version. Some members here use it extensively.

    -- richard
     
  10. flashhole

    flashhole Well-Known Member

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    No one thinks you are a dumb a$$ but they may think you are an a$$hole if you keep posting like this. This is a decent forum, please try and keep it that way. These topics generally bring lots of usefull comment and people learn from participating. No need to be abusive or start flaming people.
     
  11. backwoods83

    backwoods83 Well-Known Member

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    I'm not flaming anyone, I think words like theory, misconception, might, maybe etc.... are crap, I like fact all of the ballistics programs and quickload are good for getting close and that's it, they are never "exact" exact only happens with a lot of testing. "Fact" is I have 2 300 wm's both 10 twist one has a 24" pipe the other a 28" and with a 208 amax .015" in the lands I gey an average of 2778fps with 69.5grns Imr4350 and 2796fps with 79.5grns H1000 in the 24" I can put these very same loads in the 28" and get 2824fps avg with 4350 picking up 46fps with H1000 I can get 2964fps avg for a 168fps boost, but 4350 is more accurate, and es and sd are way better, I really have no use for H1000 but I think you see my point, I'm not going to rely on any software that any genious or any idiot may have written.
     
  12. Narceleb

    Narceleb Member

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    If you're getting a lot of muzzle flash, you're burning powder outside the gun, and you should use a faster powder.
     
  13. flashhole

    flashhole Well-Known Member

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    You may not need a faster powder to get rid of muzzle flash. More neck tension on the bullet or a crimp (both do the same thing) will aid in building pressure faster for a more complete burn. A heavier bulllet will have a similar affect.
     
  14. Fitch

    Fitch Well-Known Member

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    After using it for several years, reloading with out QuickLoad would be like shooting with my eyes shut. Used properly, it can provide a lot of insight into what will work, what doesn't work, and more importantly, why that might be.

    That said, it's a numerical simulation program based on assumptions about the process it's modeling. I have 35 years of experience as an engineer in Aerospace using numerical simulations as a guide to understanding physical systems and environments. I've learned that while simulations are seldom if ever exact, exact is not required for them to be very very useful.

    Reloading and testing in a rifle isn't exact either or all the bullets would go into one caliber sized hole.

    My QuickLoad models frequently come closer to predicting muzzle velocity than the reloading manuals, much closer in fact. Used with care, QuickLoad can predict MV +/- 2%, and sometimes within a hundred fps, a surprisingly often.

    Fitch