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Thread: .224 Valkyrie

  1. #11
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    Default Re: .224 Valkyrie

    There are various theories on barrel throat erosion. As far as I can determine, and please note, I can not see what is happening inside there while the round is igniting, there are basically 2 things that happen when a cartridge is fired that contribute to throat erosion:

    1. When the primer ignites, the bullet is pushed forward against the lands and momentarily stops there while the pressure builds up. While this is happening, some (very hot) propellant gas leaks past the bullet and squeezes through the gaps between the bullet and the rifling grooves. This should contribute to erosion of the barrel steel right there. The longer the bullet sits and the higher the pressure needs to climb before the bullet moves forward and seals the bore, the more erosion will take place per shot. Slower powders should prolong this time and increase erosion.

    2. When the bullet has moved down the barrel a little, hot burning propellant and gas is funneled into the barrel by the case shoulders and creates a concentrated flame with high-speed hot particles (partially burned powder granules) somewhere in the chamber throat area. This should cause some erosion of surface metal.

    These 2 processes occour with each shot, but exactly what portion of the barrel throat erosion can be blamed on each one will differ from one chambering to another and one load to another. There may also be other mechanisms at play here.

    It should be logical, that the longer the bullet needs to "hesitate" in the throat, and the more powder is burned, the faster throat erosion should occour. Well, that's the theory at least. Reality often differs.

    To determine a cartridge's propensity to eat barrels, one can compile a simple table. Divide the powder weight (grains) by the cross-sectional area of the barrel. The result will give you a value to compare various calibres in terms of throat erosion potential. Sort them in ascending or decending order, and you can see that the barrel-burners all sit tightly at one end of the table. This will help you to predict the wear habits of any new cartridge without much test-firing.

    One factor that does not lend itself to theoretical predictions, is the effect of bullet bearing surface length. Tests with longer bullets (75-77 gn) in 22-250 rifles (with appropriate barrel twist rates) have shown that the longer bearing surfaces help to prolong barrel life. This is because a bullet will generally shoot accurately if the jump from case mouth to rifling lands is shorter than the bearing surface. The longer bullets can accomodate a longer jump, i.e. more throat erosion. (Assuming throat erosion is constant per shot.)

    We can safely assume that the larger powder capacity of the 224 Valkyre will lead to more throat erosion per shot, compared to a 223 Rem. We can also safely assume that the longer bearing surface of the 90gn bullet will accomodate more throat erosion before accuracy starts to deteriorate, compared to a 55 - 62 gn bullet. How exactly these two variables balance out, or not, remains to be seen.

  2. #12
    Member Messor's Avatar
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    Default Re: .224 Valkyrie

    Barrel life itself means nothing, it needs other factors to make it relevant.

    If you live in a country with a strong economy, and you can buy and change out a barrel on a Saturday, then it's not a problem at all.
    You live in another country, like SA for example, it could be a problem.

    It's a cool new thing, not limited in itself, the specific human would be the limiting factor.
    "It's not the dying part that scares me, it's the not living."

  3. #13

    Default Re: .224 Valkyrie

    Case capacity very close to .223 and powder charges very similar especially compared to the heavier .223 bullets.



    http://www.handloads.com/loaddata/de...=rifle&Source=

    The sharp shoulders of the .224 V (and of course the longer neck and high bc bullets) could be part of the trick in making it as effective as it is.

  4. #14
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    Default Re: .224 Valkyrie

    Does anybody know of AR's in this caliber coming to ZA?

  5. #15

    Default Re: .224 Valkyrie

    Wilson Combat launched two models:
    http://www.thefirearmblog.com/blog/2...-224-valkyrie/


    Sent from my iPhone using Tapatalk

  6. #16

    Default Re: .224 Valkyrie

    I can see merit if you want an AR15 platform but in a bolt I would just do a .22-250 with 1:7 barrel and long leade.

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