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difficult feeding in 9 mm mak

Discussion in 'Handloading and Reloading' started by horsearcherwannabe, Sep 15, 2011.

  1. horsearcherwannabe

    horsearcherwannabe Well-Known Member

    I have a feg pa 63. With factory ammo the gun feeds with out issue.

    My question is this. What is the worst thing that could happem if a mak round indexed further forward than it should?

    Would the gun even fire?

    I am using star brass and a dillion 550 with a three set of hordady custom dies. It feels like 3.3 grains of 231 with a 100 gr copper plated bullet is going to cycle the action firmly. The problem I am having is this:
    I have to put quite a crimp on the rounds to get them to feed. :eek:
    I know the mak indexes on the rim of the case so I did not want to crimp at all. The first set of five rounds I made with out any crimp. I wrestled the first round in, fired and pulled the clip to see if any of the remaining bullets had moved. As expected I did not see any off set. I got the rest of the rounds to fire. I could cover all five rounds with the palm of my hand at 15 or so yards. For the gun and its intened use that is sufficient accuracy.

    The next day a batch of 5 got a fairly hard taper crimp and they fed. Accuracy was better. I think that was mostly because I was not force feeding the gun.

    I am going to build five each of 3.1, 3.2, 3.3, 3.4 and 3.5 gr of 231. The order of shooting will be light to heavy with brass recovery after each group. I plan on checking for flat primers and the other usual suspects
  2. rcmodel

    rcmodel Member in memoriam

    Taper Crimp does little to nothing at all to keep the bullet from getting pushed deeper in the case during feeding.

    Case neck tension is what holds the bullet in place.

    That is determined by how small the sizing die sizes the brass, and by how much the expander opens it back up.

    A proper taper crimp should straighten the case mouth bell and little more.
    A 9mm MAK case mouth should measure in the vecenity of .987" to .988" after taper crimping.

    If you need more neck tension, sand down the expander plug a little with a drill & emery cloth.

    BTW: Really excess taper crimp will squeeze down the bullet, along with the brass case.
    Then the harder brass will spring back more then the softer lead core bullet.
    Making the bullet fit looser, rather then tighter.

  3. rfwobbly

    rfwobbly Well-Known Member

    As RC told you, setting taper crimp is not a guess or an experiment. Taper crimp is merely to erase the belling you added to the case to make seating the bullet easier. That's all.

    If you want to know the correct dimension the case mouth should be after a correct taper crimp, then simply seat a bullet in a sized case which has no belling and measure the result. Then set your taper crimp die to deliver that exact same diameter. It's that simple.

    On 9 Mak, that number should turn out to be in the neighborhood of .388". Definitely no larger than .390".

    If your taper crimp is measuring in at .388 or .387" and the finished cartridge is still having trouble entering the chamber, then your chamber has issues or your OAL is too long for that particular bullet/barrel combination.

    Ultimately, how the bullet fits the barrel determines your OAL, not some number out of a book. If you change bullets or barrels, then the OAL may also change. The OAL numbers in the reloading manuals are guides, not gospel. The numbers on the reloading manual diagrams are generally SAAMI maximum (ie 'do not exceed') dimensions.

    • I highly recommend that before you start "working up your load", that you get your dies properly adjusted so that the finished cartridges fit the chamber correctly. If the cartridge is tight in the chamber for any reason, then the results of your load work will be useless.

    Hope this helps!
    Last edited: Sep 15, 2011
  4. horsearcherwannabe

    horsearcherwannabe Well-Known Member

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