260 A.i. ?

Discussion in 'Long Range Hunting & Shooting' started by JPRITT, Feb 17, 2008.

  1. JPRITT

    JPRITT Well-Known Member

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    Hi all,

    Does anyone have a 260 AI? How does it compare to the 6.5 284? Does it offer better barrel life? How much does it improve the ballistics of the 260 rem? Any advice would be much appriciated.
     
  2. 260shooter

    260shooter Well-Known Member

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    My Dad shoots a 260 A.I. and I did the load work up for it. I also shoot a 260 REM. The A.I. shines with the heavier bullets. It will push a 139 Lapua at 2960 from a 28" barrel. The best I've heard from a 260 is 2830 fps. If you don't mind fireforming brass it is an outstanding cartridge.

    260
     

  3. Coyboy

    Coyboy Well-Known Member

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    It's an excellent deer and pronghorn round, very easy to shoot well, and easy on the budget. 140 grain a-max kills well. Mine has taken 10 deer/goats in 3 years, and not one needed a second bullet. Most were over 300 and 2 over 600 yards.
     
  4. Mysticplayer

    Mysticplayer Writers Guild

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    6.5 Mystic

    My version of the 260AI is called the 6.5 Mystic and I use it for F class competition. See 6mmBR.com gun of the week #75.

    It is a very nice cartridge that delivers similar performance to the 6.5 -284 but uses much less powder. Barrel life is significantly longer. I push 139gr Scenars at 2900ish FPS out of a 30" match barrel. I can reach 3000fps but brass life is short and I don't need to really push it that hard for competition.

    The 6.5-284 will always go faster if you want to but most match bullets have a sweet spot from 2900 to 3000fps so I came up with the smallest case to do the job. The 284 case is way too big in my opinion.

    The 40deg shoulder really helps to reduce case growth. Not ideal for mag feeding but single feeding is no issue.

    Same case capacity as the 6.5 Swede which is another superb choice for a hunting rifle.

    Jerry
     
  5. LRHWAL

    LRHWAL Well-Known Member

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    This ties up with the 6.5 threads...

    Jerry, excuse my ignorance, I'm pretty certain you can assist me. As I understand it the Swede is often factory loaded below what is possible in modern rifles - not talking about hot rodding it, just loading it the the sane potential that other "modern" rifles and chamberings run.

    On that basis is there much difference between a 260 Rem and the 6.5X55? In the manuals I see the Swede is always behind, but the comments seem to imply the data is conservative for older rifles.

    What should the Swede get out of say a 24-26" Rem 700?

    Thanks for any help.

    WL
     
  6. Mysticplayer

    Mysticplayer Writers Guild

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    In NA, the Swede is most definitely underloaded due to the 'one' WWI Mauser that might blow up.

    In Europe, the Swede is loaded to much higher potential. Just snoop around for info on Norma or Lapua ammo IN EUROPE.

    The Swede will easily match the 260R. If loaded to 'warm' pressures, will exceed it.

    There are many F class shooters who choose this cartridge and have no issue pushing 139/142gr match bullets to 2900fps. This is similar to the 6.5 Mystic/ 260AI.

    Used on modern actions, the Swede offers the next size up in case displacement. With the case designed for running smoothly from a mag, an ideal 6.5 hunting rd as a few Swedes have shown over the last many decades.

    I would expect to get at least 100fps faster then comparable 260R loads.

    Jerry
     
  7. LRHWAL

    LRHWAL Well-Known Member

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    Thanks Jerry.

    WL
     
  8. JPRITT

    JPRITT Well-Known Member

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    I see that nosler is offering 260 brass now. I have never owned a "wildcat". Do you have much trouble fire forming 260 AI brass? I havent really thought about the Swede. Maybe that would be a better way to go and avoid the fire forming all together
     
  9. Mysticplayer

    Mysticplayer Writers Guild

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    Unless you are working with a center feed mag ie Savage, Accuracy int mags, you have to pay attention to shoulder angles over 30deg. Most push feed actions will cycle sharp shouldered cartridges OK. Not as smooth as conventional shoulders but enough to get the job done.

    Some Controlled feed actions WILL NOT feed sharp shouldered rds no matter what you do.

    For a hunting rifle or a working mag fed rifle, I would lean towards a 30deg or less shoulder cartridge and make up the case capacity needed by using a larger case. If you have a center feed mag, the AI's are a hoot.

    If the chamber is cut as a true AI length, a standard case can be fireformed simply by chambering. You can shoot reg ammo in the chamber to make AI brass.

    If not, you need to form a secondary shoulder before fireforming. here you must use a cream or wheat/cornmeal form of fireforming as you can't seat a bullet.

    Really not a hard thing to do. I fireform all my brass no matter the chamber to max accuracy so doesn't matter to me whether it is improved or not.

    Jerry