question about c.o.a.l. and crimp 9mm

Discussion in 'The Ammo & Reloading Forum' started by MichaelM, Mar 17, 2010.

  1. MichaelM

    MichaelM New Member

    Mar 11, 2010
    So I finally sat down and started setting up my Lee turret press and deluxe 4 die set. I'm starting out with 9mm to begin with. Using sierra #8115 .355" 115 grain FMJ bullets. The sierra literature states a C.O.A.L. of 1.100". I'm assuming this is a minimum measure? I hate to assume though. What length to you guys set your 9mm up to using similar bullets?
    Also the sierra book says a firm taper crimp. Will I acheive a firm enough crimp with the Lee FCD set up like it says in the instructions? How will I be able to tell if I have enough of a crimp?
    Thanks in advance and sorry for the newbie questions.
  2. MichaelM

    MichaelM New Member

    Mar 11, 2010
    Also I'm using the bullet seating/crimp die strictly to seat and the Lee factory crimp die to apply the crimp.

  3. armedandsafe

    armedandsafe Guest

    C.O.A.L. is, theoretically, a do-not-exceed measurement.

    You set up will crimp just fine for your cartridges, if you keep your loads within the maximums listed in your reloading manual.

    Welcome to the hobby. Prepare to be absorbed by the collective. :D

  4. MichaelM

    MichaelM New Member

    Mar 11, 2010
    I guess I'm not quite understanding. So the c.o.a.l listed in the book is the shortest length the cartridge should be or the greatest length?
  5. JLA

    JLA Well-Known Member

    Feb 26, 2007
    Heart Of Texas
    The greatest in most cases along with the recommended for each specific bullet... The SAAMI standard for the 9mm NATO round is 1.169" the 1.100" is what sierra recommends for that cartridge with that bullet... As long as they arent longer than 1.169" youre good to go... BTW, crimping and seating should be sparated procedures as often as you can do it;)
  6. LDBennett

    LDBennett Well-Known Member

    Dec 20, 2003
    Hesperia, CA
    If you can shorten the cartridge by pushing the bullet nose against the bench with a moderate push then the crimp is not adequate.

    In most manuals they list the manufacturer of the bullet in the detailed reloading data section along with the cartridge overall length (COAL) for THAT bullet. In the introductory part of the reloading data they give the Maximum overall cartridge length that is guaranteed to fit any gun's magazine of that caliber. Use the suggested COAL and never exceed the Max COAL. It is best to follow the guidelines there to assure the ammo will fit in your gun.

    If there is any doubt remove the barrel from the gun and use the chamber as a cartridge gage. Any ammo that does not drop in and full seat in the chamber is out of spec. It might also be wise to try some of the reloads in the magazine as well (out of the gun!).

  7. MichaelM

    MichaelM New Member

    Mar 11, 2010
    Ok, so im pretty sure im understanding this now.

    I set up a dummy round to the specs in the sierra book, tried it in the barrel, put it in the magazine and let the action slam on it. Everything seems to work.

    I just finished loading up 10 of the minimum loads listed in the book with bullseye, 10 min loads with power pistol, and then went to the next load with each powder and loaded 10 of each labeling what each is so i dont get them mixed up. The only thing left is to go out and shoot them i guess (fingers crossed!!)

    thanks again guys!!!!
  8. JLA

    JLA Well-Known Member

    Feb 26, 2007
    Heart Of Texas
  9. mncarpenter

    mncarpenter Member

    Nov 14, 2009
    Double check and then check again your COL. I stuck a bullet in the barrel of my CZ, from the same batch that cycled perfectly in my Cougar. Action closed on it, 1st round fired but action stuck short of full battery on the second round. I had to drive it out with a cleaning rod, now I load at 1.08 vs 1.10. LRN, 125 with a load thats not hot but accurate. Works great.(CZ's are well known to need a short COL)
  10. jim brady

    jim brady Well-Known Member

    Sep 22, 2009
    Simla, Colorado
    The C.O.A.L. given in your book is the total-over-all-length that your should seat the bullet to. If you seat the bullet deeper you will increase the pressure of the powder charge on firing. Just one voice out here saying that if your reloading book lists that as the C.O.A.L. for that tested load, you should load that bullet to that length. If you seat the bullet longer or shorter than that you are playing with pressure levels.

    Seating the bullet shorter or longer really has nothing to do with the crimp. I'd follow what JLA, LDBennet and the rest of these guys said about your crimp settings.
  11. RustyFN

    RustyFN Member

    Oct 2, 2008
    West Virginia
    I load 115 and 124 grain RN at 1.135. As far as crimp I just get rid of the bell the powder/expander die put in. This is how I setup my FCD's. I will back out the stem so I know there is no way a case can touch it. Then I run a case all the way up into the die. The die should touch the shell holder. Then I screw the stem in until I feel it touch the case. Then I lower the case out of the die and screw it in another 1/2 turn. That will be a good starting point, you can adjust from there. Also make sure your seating die is backed out enough so it isn't trying to crimp as you are seating the bullet.
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