.243 or .243 AI?

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by D.S., Jun 15, 2005.

  1. D.S.

    D.S. Active Member

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    .243win or .243AI? Which one do you guys prefer and why (Im choosing between these 2 because I will be using a short action and need sufficient velocity for LR deer and varmints. I will mostly be shooting long, heavy-for-caliber bullets (90-107)and the barrel will be a 27",1-8twst Lilja; for those who have similar combos, what kind of fps do you get?--Also what are the pros and cons of having a barrel w/ a short, custom-cut throat as opposed to one with a chamber custom-cut to your preferred seating depth?
    --THanks for responding
    --Drew Stuart
     
  2. chris matthews

    chris matthews Well-Known Member

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    With that barrel length I would go with the AI case.
     
  3. jmbn

    jmbn Active Member

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    DS- I have a Ruger #1 in 243AI with a factory Ruger 26" barrel. The only heavy bullet loads I have chronographed have been with the old Nosler Solid Bases in 100 grains, and I got 3360 with 46.5 grains of 4350. That would be IMR.

    These were hot loads but shot well. No problems, but that batch of brass (Rem) didn't do too well.

    Good luck.
     
  4. James Jones

    James Jones Well-Known Member

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    with the 27" barrel you have plenty of room to burn little extra powder of the Ackley version so I'd go with that , actualy I'd go with the Ackley version beacuse of the other benifits like case life and effecientcy.
    I have run some of the 100gr match style bullets out at close to 3400fps but found that best accuracy came in at around 3000-3200. My barrel is a 1-8 twist Hart 28" long

    What are you calling long range ??
    Have you considered one of the 6.5 cals like the 260 Rem or 6.5-284 ?
     
  5. Fiftydriver

    Fiftydriver <strong>Official LRH Sponsor</strong>

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    D.S.,

    I would go with the AI version for a custom rifle. Not strictly for the velocity increase though. There are other advantages to the AI or any improved case design, the AI is just one of the better fireforming systems out there if the chamber is set up correctly.

    Most AI rifles will shoot virgin fireforming ammo into 1/2 moa or less at 100 yards making them extremely field worthy with virgin ammo if you get in a pinch.

    The last AI round I range tested before shipping was a 6mm-06 AI. Loaded with a 70 gr Ballistic Tip in virgin 270 Win brass the rifle cut three groups at 100 yards that were in the .3"s!

    The Ai case design dramatically limits case stretching as well which will result in longer case life if you load to pressures that will not open your primer pockets.

    I would go with the 243 AI. You should be able to use factory 243 ammo with great accuracy if needed someday, a bit more velocity with 243 AI ammo over the standard. Longer case life.

    Better all around really to some degree.

    If the throat is cut true to the axis of the bore and chamber(which better both be on the same axial alignment!) I have not seen much difference between a short and long throat as long as they are cut to proper diameter for the bullets used.

    I personally like the bullet to be held by the full length of the case neck, thats what it is there for so I see no need to seat the bullets out as far as possible to get those last 2 grains of powder in the case, as far as performance goes this is really pointless and at times will adversly effect accuracy.

    IF your going to use 90 gr bullets for your light bullet, I would set the throat up to use those with their base right near the base of the neck. The longer 107s will seat below the case neck but when you want to use these different bullet weigthts there has to be some compromise and I feel seating the heavier bullets into the case a bit more is better then only seating the 90 gr pills 0.050" into the case neck.

    Just my opinion,

    Kirby Allen(50)
     
  6. D.S.

    D.S. Active Member

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    THanks a lot for responding you guys.

    1st off I absolutely love the 6mm family and for this rifle I won't consider another bore size(plus, with no regrets, ive already ordered the barrel) /ubbthreads/images/graemlins/cool.gif. Does anybody have an idea of the velocity I could expect from the standard .243w w/ this 27"bbl and the 107SMK?-be a bit conservative w/ your estimates because I hate using up bbl life trying to find an accurate max load(if there isnt much of an fps difference Ill probably just go w/ the .243w so I dont have to waste bbl life and time fireforming brass). I would really like to use the 6mmrem but Ive been told that this cartridge w/long bullets doesnt fit very well in a short action and magazine. Please tell me any of your ideas and opinions-I will seriously consider all of them
    see ya later, Drew Stuart
     
  7. James Jones

    James Jones Well-Known Member

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    You should be able to get 3000fps with handloads out of a standard 243 Win and a 27" barrel
    As for using up barrel life with fire forming , I use a fast ball powder and heavy bullet to fireform my brass. it shoot this load pretty well and it makes for a good close range hunting round and the faster ball powder isin't nearly as bad on the barrel as some guys think

    And if you realy like the 6mm case then use it , all you have to do it get a Wyatts extended box for you mag well
     
  8. chris matthews

    chris matthews Well-Known Member

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    You can buy 243 AI brass from Grayback's Wildcats in Oregon or send him brass to fire form- saves your barrel and time, etc....