Otis Gun Care
+ Reply to Thread
Page 1 of 2
1 2 LastLast
Results 1 to 10 of 15

Thread: Minimum/maxmimum case length for .45 ACP?

  1. #1
    Join Date
    Aug 2009
    Location
    NW Washington State
    Posts
    5,115

    Default Minimum/maxmimum case length for .45 ACP?

    Although I seem to have the technique down pretty well, there are still a few reloading facts I don't have figured out. One, is the length of the case. I have a Speer reloading guide and it states that the length of the (empty) case should be .898". It doesn't say if this is maximum or minimum length. The instruction sheet that accompanied my Lee Dies was a little more helpful and said that the "maximum trim length" should be .898"

    I know, that when a case gets beyond maximum length, it needs to be trimmed if you want to continue reloading it. In there a minimum length, or is that something you don't usually run into, assuming the case is in decent shape?

    Thanks, as always for your patience.

    RtL
    "We make men without chests and expect from them virtue and enterprise. We laugh at honor and are shocked to find traitors in our midst."
    --C.S. Lewis

  2. #2
    Join Date
    Aug 2009
    Posts
    1,692

    Default

    Rick the .45 acp has one trick that very few other cartridges have and that is that instead of lengthening it shrinks each time it's fired. You don't have to trim the .45 acp. It will do that all by itself but with enough firings you will finally have to discard the case as it's too short to head space properly.

  3. #3
    Join Date
    Aug 2009
    Location
    NW Washington State
    Posts
    5,115

    Default

    How do you determine if it is headspaced properly? Is there a certain minimum length? The cartridges I've reloaded are the proper length - 1.265"-1.270", as a rule. But that's total length with bullet.

    Thanks for the information.
    "We make men without chests and expect from them virtue and enterprise. We laugh at honor and are shocked to find traitors in our midst."
    --C.S. Lewis

  4. #4
    Join Date
    Aug 2009
    Location
    Northeast Connecticut
    Posts
    571

    Default

    Experienced .45 handloaders often use the pistol's barrel as a case length gauge. Remove from pistol, place empty, sized case in chamber, see if rear end of case is level with the rear of the barrel "hood". If above hood, case is too long, if below by more than about .030", it's short. (SAAMI minimum case length is .888", maximum chamber is .920" deep) After doing this a few dozen times, you'll probably discover it's a waste of time except when using the same basic idea to adjust seating depth for some cast bullets that are designed to allow the loaded bullet to stop on the rifling - permitting consistent chambering despite minor variations in case length.

  5. #5
    Join Date
    Aug 2009
    Location
    NW Washington State
    Posts
    5,115

    Default

    When you say "waste of time", what do you mean? Thanks for working with me on this.
    "We make men without chests and expect from them virtue and enterprise. We laugh at honor and are shocked to find traitors in our midst."
    --C.S. Lewis

  6. #6
    Join Date
    Aug 2009
    Location
    Northeast Connecticut
    Posts
    571

    Default

    Waste of time because 99.9% of the empty, sized cases you try in the chamber will be within the acceptable range. After a while it gets really boring. (There's also an easy way to weed out the short ones during loading. They won't get nicely belled by a well-adjusted expander and it will therefore be difficult to start bullets in them for seating.)

    Frankly, a .45 ACP case that's a little too short usually works fine, thanks to the 1911's inertia firing pin. See page 239 of Hatcher's Notebook for a practical view on the general inconsequentiality of excess "headspace" (technically, cartridge end-play) in relatively low-pressure centerfire handgun cartridges. If a case is too long (or the bullet is seated too far out for its shape and jams hard in the lands) the 1911 will simply refuse to go into battery and the round won't fire. Because the .45 ACP chamber mouth step is cut at 90 degrees to the chamber axis, rather than the usual 45 degrees or less found in rifle chambers, there's little danger of "pinching" the case mouth if it's forced into the chamber. Such pinching in rifles can entrap the bullet and raise pressure significantly - but in the .45 auto the normal consequence of pounding the slide closed (a generally bad idea) on an overlong case is a slightly crumpled case. (If you really must pound on a .45 slide, please keep the pistol pointed somewhere safe!)

    Getting familiar with the SAAMI specs, especially the length tolerances, may help to appreciate how much variation is acceptable and reduce anxiety about relatively minor factors.


  7. #7
    Join Date
    Aug 2009
    Posts
    3,310

    Default

    As Parashooter noted, practically speaking, headspace is a non-issue in the .45 ACP in the 1911. It is a controlled feed in which the cartridge feeds up the breech face and under the extractor where it is held regardless of how short it might be. Without looking, I think the reference to Col. Hatcher's comments on headspace involves firing the .380 Auto in the 9mm Luger. The shorter case feeds up and under the extractor where it is held for firing, and even though there is .072 excessive headspace, everything is normal except the .380 cartridge won't cycle the Luger.
    In real life some chambers are long and some cases are short, but it makes no difference in everyday informal shooting due to the design of the 1911.

  8. #8
    Join Date
    Aug 2009
    Location
    Northeast Connecticut
    Posts
    571

    Default

    Hatcher also reported on firing .45 ACP in the .455 Webley auto. "If . . . they are loaded from the magazine . . . they fire, extract, eject, and reload just as if they were intended for this gun, in spite of the 1/8 of an inch excess headspace."

  9. #9
    Join Date
    Aug 2009
    Location
    NW Washington State
    Posts
    5,115

    Default

    Again, I thank all of you for answering what may seem like picky questions. I like to know just what perameters to work within. I think when you're dealing with explosives in a small place (the chamber of a firearm), a little healthy curiousity is a good thing. It sounds like there is plenty of "wiggle room" built into John Browning's little pistol - but I'm still wanting to find out where that "wiggle room" ends.

    Right now, I am working on consistancy - the unprimed cartridges are in one tray; then, when they are primed they get moved to another tray face down. Then, as they are charged with powder they are face up. When they are all charged I do a quick look to make sure the levels look all the same. Then, one by one, they have a bullet seated.
    "We make men without chests and expect from them virtue and enterprise. We laugh at honor and are shocked to find traitors in our midst."
    --C.S. Lewis

  10. #10
    Join Date
    Aug 2009
    Location
    Eastern Missouri
    Posts
    7,680

    Default

    Rick, it looks to me that you have loading .45ACP down pat. You can buy a maximum case length gauge from midway or dillon. it really help when setting up the seat and crimp die.

+ Reply to Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts