Explaining Headspace

Discussion in 'The Ammo & Reloading Forum' started by Insulation Tim, Jun 6, 2010.

  1. DGG!

    DGG! New Member

    Apr 6, 2010
    So it is negative as far as headspacing .45 acp in a revolver without using a moon clip as long as you (1) like to pick them out with your fingernails or pocket knife, etc. and (2) you are not shooting any of the old .45 acp Colt model 1917 revolvers, made by the millions and used widely during WWI, that are not made with a headspace.

    Thanks for the informative reply but I think I'll stick with my moon clips for now.
    Last edited: Jun 10, 2010
  2. Alpo

    Alpo Well-Known Member

    Feb 3, 2007
    NW Florida
    They only made a little over 150 thousand, not "millions". They only did the "smooth-sided" chambers for about the first six months of production. Guns that had not been issued, when they changed over, were sent back to Colt to have new cylinders fitted.

    BUT, your question was not "should you use the clips?", or "is it easier to shoot 'em while using the clips?", it was "Don't you have to moon the .45 acp to get it to headspace in a revolver?" So, I answered that question. NO, you don't HAVE TO.

  3. upsguy

    upsguy New Member

    Jan 26, 2011
    CROOK Co. Illinois
    Ive been checking out past threads and found this one very useful. Im really glad I found this forum. You guys ROCK!!!
    BTW, this thread SHOULD be a sticky...
  4. hunter29180

    hunter29180 Well-Known Member

    like Tim I have read this in many places and as LD suggested this discussed to some degree in most reloading manuels..however...Alpo's explanation is so very concise that ther is almost no confusion inherent to it. i have always felt as if there was something i was missing in reading the reloading manuels..i now fell i really got the meaning!

    Last edited: Feb 10, 2011
  5. LesterPTelestrat

    LesterPTelestrat New Member

    Aug 17, 2010
    Diddo that hunter29189. I'm meticulous about case length when loading .45 ACP so have never had an issue. I just didn't really understand why it was so important until now. Very good thread!
    Last edited: Feb 13, 2011
  6. bluesea112

    bluesea112 Active Member

    Nov 20, 2005
    West, TX
    If the .45 acp is spaced on the mouth of the cartridge, then am I correct to think that crimping may allow the cartridge to slide too far foward without catching on the lip? I have been using a Lee factory crimp on my .45 acp, and I have not run into a problem. Now I am thouroughly confused, because what I just read tells me that I should be having a problem. What am I missing here?
  7. woolleyworm

    woolleyworm Well-Known Member

    Feb 23, 2009
    SW Fort Worth
    A taper crimp is not anything like a roll crimp, I always like to think of a taper crimp as a " squeeze " to get to the final dimension, it really just removes the flare from the seating process more than anything.
  8. Alpo

    Alpo Well-Known Member

    Feb 3, 2007
    NW Florida
    Bluesea, it really depends on the gun.

    I use the Lee Factory Crimp Die on my 45 ACPs. I have no problems with them in any of my 1911s. I can also shoot them without the moon clips in my 1917, 1937 and 625 Smith and Wesson revolvers. However, if I try to use them without the clips in my 1950 Smith and Wesson revolver, they fall past the step and will not fire. Firing them with the clips works, so I know the gun works. Using factory ammo without the clips works, so I know the step is there. But, my reloads will not work in THIS gun, without moon clips. The only thing I can come up with is that the chambers of THIS gun are at maximum size.
  9. bluesea112

    bluesea112 Active Member

    Nov 20, 2005
    West, TX
    Thanks for clearing that up guys. I forgot to mention that I am shooting the .45 acp's in a Sig P220.
  10. CampingJosh

    CampingJosh Well-Known Member

    Sep 25, 2007
    I had a fun experience in my local shop yesterday. A guy came in with three pieces of fired .223 brass. All three had the primers blown back just a bit, and one was split just about 1/4" in front of the head.
    He said that these were the first three rounds he had fired in his brand new Marlin rifle. The guy behind the counter just kept saying that the only thing that could cause that would be overcharged ammo. I asked him if he had reloaded it, and he hadn't. It was factory ammo from two different manufacturers (Remington and Winchester).
    I told him it was a headspace issue. Then the shop owner decided to call one of the guys he knew at Remington's service center in Illinois (shop owner used to be a sales rep for Remington). The phone call confirmed what I told him, and that rifle is going back to be rebarreled.
    Before I mentioned headspace, the guys at the shop had just about convinced the guy to go home and try firing it with some Federal ammo. :rolleyes: While I've now read a couple different reloading manuals, it was this thread that originally taught me about headspace. So our discussions on here are helpful to the safety even of shooters who've never heard of TFF. :)
  11. Innovative

    Innovative New Member

    Aug 14, 2009
    Headspace is the clearance in your chamber between your case head and the breech. It can be measured in several different ways, and there's a different story for each type of cartridge. Some of the most popular cartridges are rimmed, non-rimmed and belted. Here's a good article (I wrote it) that explains headspace.

    Understanding Headspace

    Headspace is different to someone that's installing a barrel, and special go/no-go gauges are needed. Chamber clearance (at the shoulder) is also important for shooters that want to make quality handloads. However, the handloader uses different tools to measure the chamber clearance that his loads have in his particular chamber.

    - Larry
  12. NEILT

    NEILT New Member

    Nov 19, 2011
    Thanks for explaining that
  13. Edward Horton

    Edward Horton New Member

    Sep 1, 2009

    And excess headspace. :eek:

  14. jack404

    jack404 Former Guest

    Jan 11, 2010
    100% correct

    all these fancy night clubs and such have way too much headspace ...
  15. madbuck22

    madbuck22 Member

    Feb 20, 2011
    san diego
    this thread has been informative and entertaining. I give it an 11.
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