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primers blown out

Discussion in 'The Powder Keg' started by Dick Robinson, Sep 1, 2002.

  1. While trying to work up a load, for my AR-15, I tried a load of 27gr. of XMR 2015 with a 55gr. fmjbt bullet. I was told, by a friend, that this load worked wel, in his AR, so I checked it, in the Lyman manual, and it was an acceptable load, so I tried it. After about the 5th round, my rifle wouldn't shoot. I was unable to pull the trigger. I removed the magazine and noticed smoke coming from the bottom, of the mag, I also noticed the unused ammo, in the magazine, was black. I then inspected some of the fired cases, and found that the primers had blown out. I found that the reason the rifle wouldn't fire was that the primers had fallen into the action and blocked the trigger. After inspecting the rifle and removing the hammer and trigger, to remove the primers, I continued to shoot, using some other ammo that I had loaded, with a different powder, and had no problems. I've been loading for about 20 years, and never had anything like this happen, before. If anyone has any ideas, I'd like to hear them.
    Thanks, Dick
  2. dave375hh

    dave375hh G&G Newbie Forum Contributor

    Just guesses without looking, 1.) Your lot of powder is different from your buddy's. 2.) Your brass is thicker, harder, smaller than his. 3.) different primers. 4.) Tighter bore in your rifle. 5.) Any or all of these differences in combination could easily run the pressures too high. The Lyman 47 book has some very hot loads listed that are often heavier than all the other manuals. That's why it pays to check several before starting a new load. I once took a load out of the Speer #8 that was one step down from max w/Norma 205 in a 25-06. That load froze the bolt, expanded the case head .011, and I never did find the primer. Just because it worked for your buddy dosen't mean the same load will work for you, you must work up, no shortcuts.

  3. Calvin

    Calvin G&G Enthusiast

    How about the primer pockets? Are you using military brass for your reloads? If so, have you removed the crimp? If not, it sounds like the primers you are using are undersized slightly. I had that happen with a batch of Remington primers before.
    As a personal side note, I always start with the minimum and work my way up. I have 3 rifles of the same caliber and they all 3 have their own favorite load. 3 grains make a BIG difference in those rifles. Had similar experiences to yours and Dave's.
    When you figure it out, let us know.....
    Last edited: Sep 2, 2002
  4. Dave & Calvin, thanks for your reply. The primers, I was using, are Winchester. I had no trouble with the same primers, in other loads. The brass I was using, is once fired F-C. A local SWAT team uses the range I use, to practice, and they always leave 1-2000 pieces of .223, .308 & .30-06 brass, when they're done.
    I know the load I used, was at the top, but extraction was normal and none, of the cases seemed to be swelled or de-formed.
    Still scratching my head, on this one.
    Thanks guys. Have a good one, Dick.
  5. dave375hh

    dave375hh G&G Newbie Forum Contributor

    Stop scratching! Your load is too hot! The ejection is controled by a metered gas system that only gets what it needs and bleeds off the rest. You didn't have trouble with those primers in other loads because the "other" loads weren't excessive. Blown primers are not a curiosity they are a danger sign! F-C is Federal brass which is usually thicker than most others. You also didn't say what your buddy was using, brass wise. Measure some of the fired cases and some unfired with a mic on the casehead just above the extractor groove. Any casehead expansion of .001 or more is a sign of excessive pressure. I'm guessing yours will show .005 to .006 to have the primers fall out into the action.

    Your playing with fire and your match is getting short.
  6. Calvin

    Calvin G&G Enthusiast

    I agree with Dave. You're gonna have to start WAY lower on those loads. If you have any more of those loads laying around, I would put the old bullet puller to use, and soon.
  7. I think, you guys, are right. I should have realized the load was too hot, guess I had a little brain fade there.
    I talked to the guy that recommended the load, and he said he thought he used military brass but he wasn't sure. In any event, he didn't know the load was that hot. We've both decided it might be a good idea to start, at the bottom, and work up. Gee, where have I heard that before? DUUUH!!!!!
    I guess the longer you reload, the easier it is to get careless. The good thing is, no one was hurt and I got a much needed wake-up call.
    Thanks for the responses guys. Have a good one. Dick