What causes hang-fires?

Discussion in 'Reloading' started by montana_native, Dec 18, 2009.

  1. montana_native

    montana_native Well-Known Member

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    I had one this morning out of a Remington 700 243 AI. Just a fraction of a second delay, but enough to make me a bit paranoid for the next few shots. That shot was about 80 fps slower than the others in the group. CCI 200 primers and H414 powder witha 105 A-max was the load.

    Thanks.
     
  2. boomtube

    boomtube Well-Known Member

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    We can't reall KNOW can we? The cause and results do get blown down the bore, eventually.

    Been guessed that tumbling media clogs some flash holes. The explosive pellet may have been crushed during seating. Or, the primer may not be pushed fully home so the pin impact is cushioned enough to retard full detonation. Or a tiny bit of the compound may be contaminated by finger oils. Or the firing pin impact may be soft due to a weak spring or crud in the bolt. Or powder demons may be at work!
     

  3. montana_native

    montana_native Well-Known Member

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    If I had to guess at one of those causes you listed, it would be the primer not seated all the way. It's Lapua brass and the primer pockets are very tight.

    Thanks
     
  4. James H

    James H Well-Known Member

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    H414 can be dificult to light in cold temps.
    I would switch to H4350 powder or CCI 250 primers.
    Either should solve the problem.
    James
     
  5. J E Custom

    J E Custom Well-Known Member

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    That much change in velocity would indicate to me that you had a bad primer.

    Some times if you handel the primer with your hand it will get contaminated with skin oils
    and doesn't ignite properly causing a delayed ignition and a slow flame propagation.

    The other thing that happens in colder weather is that the fireing pin and spring have
    to much grease on them and it will slow or stop the firing pin from striking the primer.
    but this will not change the velocity like in your case but will cause hang fires.

    There are a lot of other possibilities like under sized cases, poor primer fit,weak fireing
    pin spring and/or a short firing pin and deep seated primer combo.

    J E CUSTOM
     
  6. Mikecr

    Mikecr Well-Known Member

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    Load a fired round and pull the trigger while watching the bolt. If that handle has any rotational movement(slight twitch up or down), then energy is spent doing so.
    Just a quick check
     
  7. Doug in Alaska

    Doug in Alaska Well-Known Member

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    Wow, I've been reloading for well over 40 years and have always handled my primers. I've never had a hang-fire but you bring up a very good point I had never thought of. How do you suggest getting the primer into the primer seating cup on a RCBS machine without handling it, rubber gloves perhaps?

    Thanks,
    Doug
     
  8. fj40mojo

    fj40mojo Well-Known Member

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  9. justgoto

    justgoto Well-Known Member

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    I don't know where the thread is that I first heard this but a light charge with slow burning powder can cause it.

    Here is a thread I started a few weeks ago on my hang fire problem with H414.

    To summarize...

    I was load testing and encountered a few hang fires; not until I added 2 or so grains more powder did the hang-fires subside.

    H414 is the only powder I have encountered a hang-fire with.

    It was cold out so the comment about the cold could have been a contributor.
     
  10. Winchester 69

    Winchester 69 Well-Known Member

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    +1

    H414 is a spherical powder that requires a hotter primer to ignite. Should the problem recur, consideration of the above may be prudent.
     
    Last edited: Dec 19, 2009
  11. J E Custom

    J E Custom Well-Known Member

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    I use a Primer tray by RCBS ( a round or square dish with ridges in it and a lid ) when you
    open the primer box you dump them in the tray and shake it side to side to turn all of the
    primers upside down then place the lid on and turn it over and the primers are ready to load
    in the primer tube without ever touching them.

    If you don't have a primer tray (They are 5 or 6 dollars) and you load them one at a time
    then you can use rubber gloves or the little finger gloves that sectaries use on your thumb
    and fore finger to prevent touching the primer. I learned this the hard way when I started
    hand loading for my shotguns and had been handling the primers one at a time, I continually
    had hang fires and miss fires until I stopped touching them and have never had one sense

    I know it sounds extreme but it can save you a misfire.

    It is best never to touch your primers with your hands. They are the key to consistant pressures
    and if you accidentally alter the burn rate it will alter your SDs and ESs.

    J E CUSTOM
     
    Last edited: Dec 19, 2009
  12. bigngreen

    bigngreen Well-Known Member

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    I've had some funky primer action from priming them then letting them set in the tray neck up for a few days between loading sessions, when I started flipping them neck down they worked fine. We have a pair of mini needle point pliers for handling primers that won't flip or for single loading them.
     
  13. montana_native

    montana_native Well-Known Member

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    It was about 20°F when I was shooting. The load was pretty hot, about 0.5 gr less than a sticky bolt lift. My groups went to hell after that too. Shooting about 0.3 MOA then right after the hang-fire the last two groups were an inch at 100 yds. I might have been contributing though with my paranoia. I've had excellent luck with IMR4350 fireforming. Maybe I will switch. I just can't find that or H4350 anywhere.

    Thanks for all of the advice so far.
     
  14. Airgunner7

    Airgunner7 Well-Known Member

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    How do you correct the bolt twitching? I Have been getting some with slower fps and low 2-3moa when I notice them.
    Rem 700
    Load: 7mm Rum/85.5G retumbo/ 180 bergers/cci mag primers. This is 2-3 times fired brass.

    Both this summer and today at 40 deg. ...?


    I have never cleaned the inside of the bolt/spring....guess I should look that up too.