Dies for .280 AI

Discussion in 'Reloading Forum (All Calibers)' started by BlackHornet, Oct 28, 2017.

  1. BlackHornet

    BlackHornet

    Joined:
    Oct 28, 2017
    Messages:
    5
    Hey guys, long time lurker here and after a long time of coming here and being able to find the answers to my questions...i now have an actual question that pertains to me. I just bought a rifle chambered in .280 Ackley and when I went to order dies for it, I became aware that there are two different sets. I have attached a picture of a case that I fireformed in the rifle from factory .280 (NOT ACKLEY) and I took some measurements with my dial calipers in hopes that the fellas here could see what I do not know.

    Question: which dies do I need to order to properly reload for this chamber

    thank yall!!!

    .280AI fireformed dims.PNG .280AI fireformed primer.PNG
     
  2. msinc

    msinc

    Joined:
    May 14, 2011
    Messages:
    1,947
    If the rifle is chambered in 280 Ackley Improved then you need 280 Ackley Improved dies if you want to realize the benefits of the improved chamber. You can use 280 Remington dies and it will shoot fine, but the cases will be fire forming to the improved chamber. Ideally, you should really have both if you are going to reload for this rifle. You will probably want to reload some standard 280 Remington used brass at some point and it's best if you full length size them and load to fire form. Having a 280AI, or any other "improved" chambered rifle and only shooting factory ammo {parent case} in it is like having a turbo charged hot rod but blocking the turbo so it don't spin up.
     
  3. Sniper338

    Sniper338

    Joined:
    Aug 14, 2014
    Messages:
    2,990
    just 280AI dies...

    whidden full length sizer and seating dies, or redding type S full length sizer bushing die, and wilson hand die seater.

    depends which route you plan to take.

    fire form all your brass, then trim them to the same length. then you wont have to trim much or often being it AI.
     
  4. BlackHornet

    BlackHornet

    Joined:
    Oct 28, 2017
    Messages:
    5
    Thank you for the response and I totally agree with you on the only shooting non-improved out of an ackley. This isnt my first AI. Since I already reload and this is a bolt gun, I dont understand why one wouldnt do an ackley.
     
    msinc likes this.
  5. BlackHornet

    BlackHornet

    Joined:
    Oct 28, 2017
    Messages:
    5
    Thanks for the response guys!

    Im just not sure which dies to order (.280 ackley improved or .280 improved 40* shoulder). When I found out that there were two different dies available to order, I started doing research online and came up with the difference between the two is .014" in headspace....sound correct? Well, I dont own another .280AI and so I cant compare fireformed cases to see which chamber I have.
     
  6. BlackHornet

    BlackHornet

    Joined:
    Oct 28, 2017
    Messages:
    5
  7. Ringostar

    Ringostar

    Joined:
    Apr 19, 2011
    Messages:
    1,477
    Have you done a thorough search here? The case has been argued many times in the past. Dave Kiff from PTG showed that there wasn't a difference between the old 280AI and what was later set up as a sammi spec. Iirc the .014" difference was a minimum to maximum change. Why Redding offers 2 different dies, I don't know. You will probably have to call them with your fired case measurements and ask them which die would fit.
     
    gunsandgunsmithing likes this.
  8. BlackHornet

    BlackHornet

    Joined:
    Oct 28, 2017
    Messages:
    5
    I have done a search and I suppose there was always somebody still bringing up the "issue" and when it comes to forums, it's hard to know who's credible or not. So I then started looking at dies and saw multiple part numbers and so that told me that there, still, could be a discrepancy...so I figured I would ask the place where I've come to many times before for reloading information.
     
  9. Willie

    Willie Gold $$ Contributor

    Joined:
    Feb 3, 2017
    Messages:
    581
    If you bought this rifle used, try to check with previous owner for a reamer print or some brass that's fired several times. If you have have only once fired 280 rem brass ( fire forming ), it may not be completely formed. Still, you need to measure your base to datum length with a comparator and call Redding for some tech help, prior to buying a die.

    If this is an older rifle, it could well be chambered by any of the numerous 280 Ackley reamers that were made. Better be safe than sorry! If the barrel stamp doesn't say 280AI, it could be an old type. Use the .375" comparator to get the base to datum measurements on your fired brass.
     
    Last edited: Oct 28, 2017
  10. msinc

    msinc

    Joined:
    May 14, 2011
    Messages:
    1,947
    Redding carries two because they had the old style 40 degree dies left over. If they hadn't offered ones titled to the new nomenclature once it went SAAMI then there would be those that wouldn't buy them. It is confusing, but both are identical as already noted. As above, and as far as I am concerned, the only way to reload for rimless AI cartridges is with a comparator...and not just any comparator...it should be sized to the junction of the neck and shoulder exactly where the case headspaces. You can do it using a headspace gauge and any datum that hits the shoulder, but I like to use the chamber reamer to make my own comparator the same as the chamber itself.
     
  11. Killitgrillit

    Killitgrillit

    Joined:
    Nov 16, 2014
    Messages:
    25
    I have the old style chamber in my rifle, I will try to measure a fired case today if I remember and let ya know.
     
  12. ImBIllT

    ImBIllT

    Joined:
    Jun 1, 2008
    Messages:
    326
    It appears that the new dies were built .014" shorter by Redding than they made their new dies. That means you can use the new dies with either chamber. Just set up your sizer to give .002"-.003" shoulder bump, and it won't matter if you die is .014" above the shell holder. On the other hand, if you use the longer dies with the shorter chamber, you won't be able to move the shoulder back. Properly adjusted the new dies will work for either chamber.

    If both dies are actually the same, then it doesn't matter, but either way, the new dies will work fine. Just don't ever set up a die to size a case as far as it possibly can without measuring how much you're moving the shoulder, no matter what cartridge you're talking about. The die and the chamber could be a poor fit and cause an excessive headspace situation even without cartridge confusion.
     
    Willie likes this.
  13. Killitgrillit

    Killitgrillit

    Joined:
    Nov 16, 2014
    Messages:
    25
    My chamber is old style and my brass is measuring.014-.016 longer than the measurements in your photo!!
     
    BlackHornet likes this.
  14. fguffey

    fguffey

    Joined:
    Feb 25, 2011
    Messages:
    2,328
    If there is one thing a reloader on this forum understands it is there is no standard for datums, with one exception, and then there is 'zero', I know of no one that makes datums that can be zeroed, with one exception.

    F. Guffey
     
  15. butchlambert

    butchlambert Site $$ Sponsor

    Joined:
    Jan 18, 2005
    Messages:
    6,943
    My 280AI dies are Redding 84428. My brass measures about lke yours.
     
  16. shoot4fun

    shoot4fun Gold $$ Contributor

    Joined:
    Feb 13, 2005
    Messages:
    1,423
    I went thru all this a little over a year ago. Nosler SAAMI specs call for a chamber .014" shorter than the original wildcat. Redding's dies are now made to work with that difference. I called Redding before ordering dies to see which set was which. They said part numbers were the same but dies for SAAMI spec were labeled 280 Ackley Improved. They also said most all vendors are sold out of the old dies and places like Midway (who sells a lot of dies) would for sure have the dies I needed.
    They did but, if not, the work around is a different shell holder (#14 I think) that can take care of the difference.
     
  17. butchlambert

    butchlambert Site $$ Sponsor

    Joined:
    Jan 18, 2005
    Messages:
    6,943
    Different shellholder? Why?
     
    msinc likes this.
  18. fguffey

    fguffey

    Joined:
    Feb 25, 2011
    Messages:
    2,328
    Difference? RCBS has a Special Order Catalog, I suggested the OP measure the angle of the shoulder, in the RCBS special order catalog they list two different dies, one with a 30 degree shoulder and the other with a 40 degree shoulder. The one thing about the angle of the shoulder that does not change is the datum, the datum is .375", I should say my datums for that chamber is .375". The difference between the shoulder angle of the two chambers will change the length of the case from the shoulder/case body juncture and the length of the neck from the shoulder/neck juncture to the end of the neck.

    RCBS has foot notes in the bottom right hand corner of ever page in their catalog of their special order dies for sizing. The triangle indicates there is more than one version known to exist and the circle with a number inside of the circle indicates the angle of the shoulder. JGS print is indicated by a diamond.

    And then there is this thing that confused reloaders; the length of the case from the datum to the case head may not change but the length of the case from the case body/shoulder juncture can change, same for the length of the neck from the shoulder/neck juncture to the end of the neck.

    My favorite improved chamber is the one cut from a short chamber, some take short cuts, they ream the chamber without setting the barrel back. The Improved reamer will not clean up all of the old chamber because the neck on the Improved chamber is longer than the neck on the standard chamber.

    F. Guffey
     

Share This Page