9mm crimp question

Discussion in 'The Ammo & Reloading Forum' started by merrill, May 3, 2009.

  1. merrill

    merrill New Member

    Joined:
    Mar 2, 2008
    Messages:
    96
    Location:
    Nashville, TN
    I am new to loading for autoloading pistols and am wondering how much crimp should be placed on the cartridge? If the bullet is deformed slightly where it is crimped is that dangerous and if not, what is the disadvantage of doing so? Thanks for any help you can give. BTW the pistol is a KalTec PF9 and I am using 6 gr. of VihtaVuori 3 N 37 under a 115 gr. bullet which according to the Lee manual is a mild load.
  2. gdmoody

    gdmoody Moderator Supporting Member

    Joined:
    Sep 7, 2007
    Messages:
    12,439
    Location:
    Northeast Georgia
    I personally would back off a little on the bullet seat/crimp die. I don't think that the bullet should be deformed after crimping. You basically want a very slight crimp, just enough to hold the bullet in place so it doesn't move when the gun is fired.
  3. merrill

    merrill New Member

    Joined:
    Mar 2, 2008
    Messages:
    96
    Location:
    Nashville, TN
    Thanks gdmoody I was getting setback and badly cratered promers and could not figure out why I assume that as a result I was compressing the load hence getting high pressures so I increased the crimp but was getting slight deformation of the bullet.
  4. gdmoody

    gdmoody Moderator Supporting Member

    Joined:
    Sep 7, 2007
    Messages:
    12,439
    Location:
    Northeast Georgia
    I don't know it for sure, but I would imagine that if it were heavily crimped, that could cause higher pressures. I just looked in my Hornady #7 Manual and it shows that the maximum charge for the Viht 3N37 for a 115 grain bullet to be 5.9 grains. Try backing off about a half a grain of powder.
    Last edited: May 3, 2009
  5. TranterUK

    TranterUK Guest

    I always thought you never to crimp 9mm. It should be tight enough after re sizing. Test a loaded round by pressing hard against a bench. Clearly if the bullet pushes in, pull it, dont fire it.
  6. Alpo

    Alpo Well-Known Member

    Joined:
    Feb 3, 2007
    Messages:
    11,758
    Location:
    NW Florida
  7. LDBennett

    LDBennett Well-Known Member

    Joined:
    Dec 20, 2003
    Messages:
    6,805
    Location:
    Hesperia, CA
    TranterUK:

    All semi-auto cartridges NEED to be taper crimped. The die sets normally do that IF you set them up correctly. The instructions packaged with the die set help you get it right.

    But it is true that in more recent times die manufacturers have made the die sets so as to produce a tighter fit of the bullet into the case. In 9 mm cartridges you often can see the end of the bullet through the case because of this tightness of fit. But regardless, the case mouth of those semi-auto cartridges need to be taper crimped as well. Follow the direction for the die sets and it happens automatically.

    LDBennett
  8. TranterUK

    TranterUK Guest

    Interesting. I have reloaded 9mm and .45acp over a long period and assumed the resizing itself produced the hold, setting the resizing die 1/2 turn back from the shell holder. When reloading such a .44 .38 .357 a small crimp was always required.

    Perhaps I need to re read the instructions, if I can find em.

    Actually I have to say, I have a lot of odd dies and was confused by a third marked 9mm that seemed to have a spreader, to bell the shell mouth. I assumed it was for loading lead, to prevent slicing?
    Last edited by a moderator: May 3, 2009
  9. merrill

    merrill New Member

    Joined:
    Mar 2, 2008
    Messages:
    96
    Location:
    Nashville, TN
    I appreciate all of the responses and will try your suggestions.
  10. Kestral

    Kestral Member

    Joined:
    Aug 31, 2008
    Messages:
    416
    Location:
    Guernsey Channel Islands
    I always finish my 9mm rds & 38 specials, with the Lee full length carbide crimp die for each calibre,I usually reload 500+ at a time and have no problems when shooting them.It also removes any small bulging near the base of the round,which sometimes occurs.
  11. olmossbak

    olmossbak New Member

    Joined:
    Feb 12, 2009
    Messages:
    212
    Location:
    NE Tenn
    I agree with Tranter and do not crimp for auto loads. I tried it early on with a taper crimp and had missfires in my Glock although the H & K is seemingly more forgiving. With the auto rounds headspacing on the case mouths one must be very careful to avoid over-crimping.

    I would think that it would be necessary only for very heave loads if needed at all.

    I pur a rather heavy crimp on all loads for revolvers, especially 357
    Last edited: May 3, 2009
  12. Kestral

    Kestral Member

    Joined:
    Aug 31, 2008
    Messages:
    416
    Location:
    Guernsey Channel Islands
    Although I use carbide dies,I still use a very small amount of case lube as well.It makes resizing so effortless when sizing large quantities. I also bell the neck just enough so that the bullet will sit upright and not topple over before seating it to its correct depth.Then I use the Lee crimp as mentioned before,a 10min run in my 2200 Turbo polisher,which removes any remaining lube etc.Have used this method for about 7 years now with very good results.
  13. jacksonco

    jacksonco New Member

    Joined:
    Jul 11, 2007
    Messages:
    2,236
    Location:
    Jackson County West Virginia
    Good info here from you guys. I always put a slight crimp in my 45 auto. I load 45-70 that for my 1895 I put a crimp in them but for my Pedersoli Rolling block I don't crimp.
  14. LDBennett

    LDBennett Well-Known Member

    Joined:
    Dec 20, 2003
    Messages:
    6,805
    Location:
    Hesperia, CA
    I've reloaded for 9 mm and other semi-auto calibers (like 45 ACP) for over 20 years in great abundance. I have reloaded for at least ten different guns (but no plastic Glocks or other plastic guns) and not one has ever had a problem with taper crimped cartridges. If a Glock has trouble with taper crimping (assuming the dies are set up per the instruction that come with them) then Glocks are made outside industry standards or your particular Glock has a problem.

    Rounds in the magazine awaiting firing are subjected to up to 16 recoil excursions in some guns and relying on the neck tension to retain the bullet is unsafe.

    For bolt or single shot rifles crimping of any kind is not necessary unless the ammo is to be subjected to rough treatment before firing or while in storage. Crimping is not optional for lever guns or guns that store the ammo end to end in the feeding tubes or for heavy recoiling guns where recoil can set the bullet back into the case and increased pressures to dangerous levels. Most semi-auto center fire pistols fall into that category of must crimp.

    Every body get to choose to do reloading their own way but some of these "maverics" of reloading fail to understand the dangers involved. They had better re-read the reloading manuals and better understand the process and the dangers for their own safety and that of others around them at the range or shooting place. All the reloading manuals can not be wrong and I think they all agree to when and how to crimp cartridges.

    LDBennett
  15. merrill

    merrill New Member

    Joined:
    Mar 2, 2008
    Messages:
    96
    Location:
    Nashville, TN
    I have adjusted the die in accordance with the instructions or as I perceived the instructions and the only way I can keep from getting setback when I chamber a round is by using a slight roll crimp. I adjusted the crimp by adjusting the seating die 1/8 turn at a time Then testing for setback by chambering a round. The rounds are hard to eject. The average person could not operate the slide when the OAL is set to that recommended by Lee. When using a taper crimp I cannot push the bullet farther into the case by pressing it against my bench; If I chamber a round set to recommended OAL and it has a taper crimp it will be setback .056 inches and will be extremely hard to eject. If I seat the bullet deeper than recommended oal it will chamber and maybe the average man could eject the round. For example if I seat to 1.142 (Lee recommendation) when I chamber the round it will be setback to 1.086 in and that is using a taper crimp that has been tested by pressing the bullet against my table top with force. If I use a slight roll crimp at 1.110in. It will not setback but as I said the average man could not eject the cartridgE.
    Guys, I thank you again for your suggestions and would welcome any others. This has got me stumped. I forgot to mention that the ogive on the bullets is closer to the front of the bullet than factory ammo which functions fine.
    Last edited: May 4, 2009
Similar Threads
Forum Title Date
The Ammo & Reloading Forum Crimp question Oct 6, 2013
The Ammo & Reloading Forum Lee factory crimp die question. Jul 22, 2013
The Ammo & Reloading Forum Question: How much "grip" needed on crimp May 14, 2012
The Ammo & Reloading Forum crimping question Mar 24, 2012
The Ammo & Reloading Forum noob question about crimping. Mar 11, 2012

Share This Page