Headspacing Ackley??

Discussion in 'Gunsmithing' started by cahunter805, Jun 25, 2010.

  1. cahunter805

    cahunter805 Well-Known Member

    Jun 18, 2010
    Hey guys. Just a quick question. I am having a 243AI barrel installed on my rem700 by a local gunsmith. Today he told me that he was checking the headspace with a regular 243win go/no go gauge. Can this be done? I was under the impression you need a different set of gauges. This is my first attempt at an ackley. Is this correct?? Thanks.
  2. Coyboy

    Coyboy Well-Known Member

    Jan 30, 2005
    The 243 ackley go is about .004" under the 243 go.

    So it is posible to set the headspace with a 243 GO gauge and proper measuring, the 243 nogo is damm near useless.

    It is always a nice idea to buy x number of brass from the same lot that you want to fireform. And give it to the smith before he chambers your barrel then he can set up the chamber to give you a slight crush fit on the brass, which is the point of going between '002-.004 under a standard 243 go gauge. I have found that with some brass .004 under is just too much crush and causes excessivly stiff bolt closure. That way if I have the brass I can eliminate any issues the customer may have by making sure everything works as it should.
  3. J E Custom

    J E Custom Well-Known Member

    Jul 29, 2004
    +1 Coyboy is dead on.

    I to like using the go gauge to get close and then as soon as the bolt will close on the brass
    that you intend to use it will have basically no head space and the brass will last a lot longer.

    I someone intends to buy factory ammo only I use the same technique only with .001 or .002
    thousandths head space on the factory ammo. (Note: the factory ammo is smaller than SAAMI
    specs so that it will fit in any chamber.

    Go gauges are cheep (Normally $35.00 to $40.00) and you can buy one to match the reamer
    used for the chamber from the same reamer manufacture.

    Some AIs have the shoulder moved forward and others have the same neck to shoulder to
    case head dimension as the parent case and these can use the same head space gauge as
    the standard case. but you need to know which one/type you have.