1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Power pistol sure is heat sensitive.

Discussion in 'Handloading and Reloading' started by jr_roosa, Sep 20, 2012.

  1. jr_roosa

    jr_roosa Well-Known Member

    Not really above published max but clearly hotter than it should be, so:
    I was chronying some loads today and though I'd run a mag of my carry ammo through, why not?

    Win 45acp brass, colt rail gun, fed lp primers, 7.0 grains of power pistol, Hornady 230gr HP-XTPs. Usually goes about 850 fps.

    I got 963. I had left my carry mags on the bench in the sun and they got warm.

    Cooler rounds from the box in the shade ran a more tame 895. Still a little more juice than I like.

    Note that the Hornady manual says that these should go around 840 or so.

    Combine this with my previous data with the 7.6 max loads running near 1100fps and it makes me think about dialing back a little more.


  2. Slamfire

    Slamfire Well-Known Member

    Colorado?! Does it break 80 F there? How hot was it when you were shooting?


    All powder produces more pressure when hot.

    All powder produce less pressure when cold.

    I have blown primers on rifle ammunition developed and tested at 70 F, when I shot the stuff in 90 + F weather in matches.
  3. Certaindeaf

    Certaindeaf member

    Bring an ice chest next time and get/have them cold. That'd be interesting.
  4. Reloadron

    Reloadron Well-Known Member

    Not unusual to see match shooters show up with their ammo in a small cooler. The idea being to maintain the ammunition at about a constant temperature regardless of what the outside air temperature is on any given day. Consistency is what it is all about.

  5. jr_roosa

    jr_roosa Well-Known Member

    It was only 75 but the mag in the sun was hot to the touch.

    We are much closer to the sun up here, you see... ;)

  6. Certaindeaf

    Certaindeaf member

    I hear you and don't doubt you. I used to compete and win on the national level and never seen that though. I understand about consistency.
  7. bluetopper

    bluetopper Well-Known Member

    When Hornady or any manual lists velocities for a certain load/bullet combination that is not necessarily what "should" happen when you try it. I learned a while back that reloading manuals are merely a guide, not a Bible.
  8. edfardos

    edfardos Well-Known Member

    40s&w with aa#5: 875fps cold, 950fps warm

    I was surprised too, but then my chrony changes from day to day also (consistent but inaccurate)

  9. jjjitters

    jjjitters Well-Known Member

    I've always devolped my rifle hunting loads by putting ten in the freezer,0F-5F and ten at normal temps for fall,around 50F. That way I could know how they shoot and group under "normal" hunting conditions uo here in the north. I general keep my pistol ammo out of the vehicle unless going to or from shooting, if I don't go into the backyard.

Share This Page