Inline FabricationMidSouth Shooters SupplyRotoMetals2Wideners
RepackboxTitan ReloadingLee Precision

Results 1 to 8 of 8

Thread: Trouble with sizer die leaking

  1. #1
    Boolit Bub bpost1958's Avatar
    Join Date
    Mar 2008
    Southern Ohio

    Trouble with sizer die leaking

    I have a Lachmiller sizer and have several RCBS sizer dies for it. The trouble I am having is with the .357 die sizing 124 Gr. RN 9MM bullets. It squirts more lube out of the bottom of the die than it puts on the bullet. This is a single lube groove bullet and does not require much lube and does not go very deep into the die. Is there something I can do to the die to stop or reduce the amount of lube that is coming out of the bottom of the die, making a mess. I am not sure if it is coming out around the die itself or along the plunger within the die. The lube is 50/50 alox beeswax.


  2. #2
    Boolit Grand Master

    Winger Ed.'s Avatar
    Join Date
    May 2007
    Just outside Gun Barrel City, Texas
    Yeah,,,,I never fell for that powder coating fad that's going on now either.

    Your issue could be a couple things:

    Lube being too warm can do it.
    Sometimes pressing a shotgun pellet into the lower holes of the die will stop it too.
    I have one that I got mad and welded up the lower holes because I didn't have the right size bird shot pellet.

    When the boolit is all the way down into the die, you don't want or need any holes in the die to line up and be
    under the lube groove. The boolit base makes a very good lower grease seal in there.

    Also, running the boolit down into the die farther than it really needs to go can sometimes do that.
    As well as just putting too much pressure on the handle when the boolit is down in there.

    The first thing I'd try is turn the handle just enough to push lube about 3/4 of the way around the groove for a few,
    then turn the handle a tiny bit more each time until the lube just fills the groove 99-100% .

    When you get the right amount, you'll get a feel for how much pressure to put on the handle.
    Last edited by Winger Ed.; 03-18-2023 at 01:07 PM.
    In school: We learn lessons, and are given tests.
    In life: We are given tests, and learn lessons.

    OK People. Enough of this idle chit-chat.
    This ain't your Grandma's sewing circle.
    Back to your oars. The Captain wants to waterski.

  3. #3
    Boolit Buddy super6's Avatar
    Join Date
    Jun 2013
    What size are the slugs dropping at? I always thought a die should be .357 and final size, I would think any thing smaller than .359 would not size correctly? And much less hold a thin lube.
    Give me something to believe in. Poison

  4. #4
    Boolit Buddy
    Join Date
    Mar 2005
    Agree with Winger Ed. IIRC #6 shot fits. One more thing to check: does this sizing die do the same thing with other bullets? You might want to clean the die and check the fit of the central rod. (I can imagine a rod smaller than correct, i.e. a loose rod, could be a problem.
    Just because change doesn't make a difference doesn't mean that change is bad.

  5. #5
    Boolit Master
    Join Date
    Jan 2011
    NE Kansas
    You really do need to determine the source before anyone can make a reliable suggestion on how to stop the lube leak. Remove the die, clean with solvent and see if the I portion of the H I combination is floppy loose or just slide smoothly in the sizer body. If the inner portion of the lube die is worn excessively, you need a new die.

    If the cast bullet is too small and does not completely fill the sizer, you will get lube passing by the driving bands. That is pretty clear when looking at the bullet because there will not be a sharp edge on the driving band. Fix the mold issue.

    If the bullet lube is appearing on the top of the push out rod ( I portion of the H I Die) then you need to adjust the stop so that the bullet is held against the rod when pressed fully into the die when lube sizing. Hold pressure on the nose of the bullet until you are ready to move the press handle to eject the bullet.

    If the lube is passing out around the size die body and the cast housing of the lube sizer, check for cracks or damage to that part where the size die has a taper fit into the cast housing. If it is none of the above, please clearly describe what you are seeing.

    Sometimes the use of a heater can allow the lube to become too liquid and pass through small gaps where it would not at a normal temperature. Also as has been mentioned, excessive pressure on the lube pressure rod can exacerbate the problem.

  6. #6
    Boolit Bub bpost1958's Avatar
    Join Date
    Mar 2008
    Southern Ohio
    The RCBS die has only one set of holes near the top of the die, the lubing of the bullet is not the issue I am having. The issue is the lube coming out of the bottom of the lube die, I am not sure if the RCBS dies need a base O-ring or not. The old Lachmiller dies have a flat bottom, the RCBS has a chamfer of about 45 degrees on them. The die plunger seems to be snug in the die body, I did clean the die well checking for slop in the plunger with no improvement. I might just have to buy another .357 lube die and see if that fixes the issue. It leaks about 10 times the lube out of the bottom of the die than it puts on the bullet. Do the Lyman lubers take the same dies as the Lachmiller/RCBS lubers do?

    I do not use a heater, it is not needed.
    Last edited by bpost1958; 03-18-2023 at 04:48 PM.

  7. #7
    Boolit Buddy
    Join Date
    Mar 2020
    Could the piston be upside down or have a piston too small? <mixed up.>The dish goes to the top.<if it has one> The nose should maybe lower in the die? Not anything to wear out on a lube sizer die other than the top 0 ring. I have 8 lubesizers and none have any seals on the bottom. I size .4315 boolits with a .432 die and no leak. Could the lube too thin? To much pressure? Just thing to look for. I do have some RCBS lube dies that work with my 450's. My RCBS .357 sizer piston measures .356 #82222 and has one lube ring with 4 holes.
    Last edited by 45DUDE; 03-18-2023 at 08:22 PM.

  8. #8
    Moderator Emeritus

    JonB_in_Glencoe's Avatar
    Join Date
    Mar 2010
    Land of 10,000 Lakes
    well, it could be one of two things.
    1. Your die isn't seated properly in the press
    2. The OD of the bottom of your die is undersized.

    to answer your other question.
    Lyman dies, while not identical, are similar enough to work in RCBS presses...most of the time.
    All Lyman dies have the 45º chamfer on the bottom, and that is how they seal on the Lyman Presses.

    You will have to investigate your old Lachmiller press, after you remove a die and clean the lube off of it. It should be obvious if your press will seal with other dies...or not. Maybe you will have to use only old Lachmiller dies.
    “If someone has a gun and is trying to kill you, it would be reasonable to shoot back with your own gun.”
    ― The Dalai Lama, Seattle Times, May 2001

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
Abbreviations used in Reloading

BP Bronze Point IMR Improved Military Rifle PTD Pointed
BR Bench Rest M Magnum RN Round Nose
BT Boat Tail PL Power-Lokt SP Soft Point
C Compressed Charge PR Primer SPCL Soft Point "Core-Lokt"
HP Hollow Point PSPCL Pointed Soft Point "Core Lokt" C.O.L. Cartridge Overall Length
PSP Pointed Soft Point Spz Spitzer Point SBT Spitzer Boat Tail
LRN Lead Round Nose LWC Lead Wad Cutter LSWC Lead Semi Wad Cutter
GC Gas Check