243 barrel length vs powder

Discussion in 'Reloading' started by bolski, Apr 28, 2013.

  1. bolski

    bolski Member

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    Ive got a 243 ruger with a 19in lightweight barrel. I m new to this and never took into consideration if barrel length and size for powder choice. I was planning on using RL 17 with a 75 gr hornday v max with Federal primers. how much difference does barrel length make in powder burn rates if any? ANy suggestions here? thanks
     
  2. AZShooter

    AZShooter Well-Known Member

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    I have read on several occasions that the optimal powder will work regardless of barrel length. There is an idea floating around that a short barrel requires a faster powder and it is nonsense. Just look in the loading books for a powder that works with best accuracy/ top velocity and make your loads.
     

  3. Sully2

    Sully2 Well-Known Member

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    A very slow burning powder cant be consumed in a short barrel and just gets thrown out the muzzle. That and a fire ball 3 feet long because its burning outside the barrel itself
     
  4. Sully2

    Sully2 Well-Known Member

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    I cant tell you is RL 17 is the right powder for you...BUT...with such a short barrel you do need to use a faster burning powder to get all you can.
     
  5. bolski

    bolski Member

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    Ive got 4007 ssc also that sounds like its going to be a better match. So is RL 17 out of the question for 22250? Ive got no problem finding these powders. guess we are lucky here.
     
  6. Sully2

    Sully2 Well-Known Member

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    RL 17 isnt listed for use in a 22-250.......and in a 243 its only Alliant data says use a 24" barrel..
     
  7. Bart B

    Bart B Well-Known Member

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    Rarely does a powder given the highest velocity also produce best accuracy.

    Only if a loading book's load is tested in a barrel exactly like yours (same chamber, bore and groove dimensions) would I think it might be the most accurate. And then only if it was tested in a free recoiling machine rest to eliminate the shooter's errors that are always part of the group size. There are thousands of loads in print for a given bullet that's stated as "most accurate." And hundreds of ways were used to determine accuracy, too. Few, very few accuracy tests used for puglished load data are made that have high enough levels of probablility that the represent what can be attained all the time. Which one's best for you?

    And if one wants their load's pressure curves to be repeatable at bullet exit for all rounds fired, they will use a powder speed correct for their barrel length. 16 inchers need different powder speeds than 28 inchers.
     
  8. AZShooter

    AZShooter Well-Known Member

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    Bart,

    You are right. Should have typed it best velocity OR accuracy. or perhaps AND/OR as I have some rifles that give some fantastic velocities AND excellent accuracy. ( RL-33 and RL-17 come to mind)

    Sully 2:

    I stand by my comment on not trying to go with a faster powder just because the barrel is shorter.

    The follow may clear up this misconception:

    Excerpts from thread on Shooter's forum:

    link: Burn rate and Barrel length - Shooters Forum

    Rocky Raab's
    Beartooth Regular Join Date: Jun 2006
    Location: Utah
    Posts: 3,316

    Nope, in all respects. It's MUZZLE FLASH THAT CONVINCES PEOPLE that powder is still burning. But if you believe the Naval Weapons Lab knows anything at all about ballistics, Muzzle Flash should convince you that flash is something else entirely.

    ----------
    Naval link on muzzle flash:
    Muzzle Flash

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    Burn rate and Barrel length

    While perusing this forum I found a comment by Rocky Raab that seemed to debunk my assumtion that faster burn rate powders would perform best in shorter barrels(and vise versa) for a given cartridge. Upon some more searching I found this nugget from Unclenick that sums it up very nicely. It seemed like it should be brought out into the light a little more in a separate thread. The amount of knowledge shown here on this forum is amazing. Thanks to all those who take the time to share!

    "On barrel length: Depending on the powder, in typical rifles peak pressure occurs when the bullet has moved somewhere between one and three inches down the bore. Just before reaching that peak, the initially ignited powder will switch over frôm progressive to digressive burning, at which time the remaining burning powder mass is around 20% or so. That number combines the tiny digressively burning pieces with the powder thrown forward with the bullet that never got started burning very well in the first place (the stuff that burns when you put a match to floor sweepings at an indoor range; not recommending you do that, btw—lead hazard). It burns in ever decreasing temperature and pressure, so it doesn't contribute much to velocity. Once the bullet has got maybe five or six inches down the barrel, you could stop burning the rest and would still get to about the same muzzle velocity as if you'd left it burning.

    The result of the above is, until you get down to a barrel length under around five or six inches, the same powder that produces the most velocity in a long barrel will also produce the most velocity in a shorter barrel. Period. So, be clear that if you move to a faster powder for, say, a 16" as opposed to a 24" barrel, you are doing it to reduce muzzle blast and recoil. That can help accuracy, so it is often a good idea frôm that standpoint, but it will come with a velocity penalty."

    ----------------Rocky Raab Rocky
    Beartooth Regular Join Date: Jun 2006
    Location: Utah
    Posts: 3,316

    It's nice of you to try, but that burn rate/barrel length myth is more intractable. obdurate, and pernicious than crabgrass.

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  9. Sully2

    Sully2 Well-Known Member

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    I frankly dont give a damm what powder he uses. But if he insists on using a 19" barrel with slow burning powders....he has just his own fate to deal with!
     
  10. AZShooter

    AZShooter Well-Known Member

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    Fate?
     
  11. TJAY

    TJAY Well-Known Member

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    AZshooter

    You will never change the idea of some that short barrels need fast powder.

    I load for a 20" barrel 243 and powders in the 4350 to 4831 range work very well. For bullets less than 85 gr. I think I would first try 4007 as I have had very goods results with it in several rounds.

    bolski, try them both and go with what works.
     
  12. bolski

    bolski Member

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    WOW, thanks guys. I really want to thank everyone for their opinions. I have heard more good about the 4007 working better for my combination any way. I am in process of trying to trade out this bottle of RL17, (dont want to break seal). gun)