+ Reply to Thread
Results 1 to 9 of 9


  1. #1
    Site Contributor Contributing Member
    Join Date
    Mar 2004
    Location
    Poulsbo, Washington
    Posts
    3,589
    Member #
    32
    Thanked
    22 times

    LAP A BULLET MOLD & SIZER TO INCREASE SIZE

    Lee mould in 45-70 The 405 Lee measured .457. My bbl slugged at .4585. So I needed to be about .003 larger.

    Check your bullets for roundness before you start lapping. This will be a good guideline for checking roundness later when you start lapping. You may even improve on the bullets roundness by lapping.


    Make a few good hardcast bullets. While your mold is cooling, drill a small hole in the base of one of the bullets as close to exact center as possible. Use a lathe if available. (Best)

    If it is off center you can ruin up your mold.

    Chuck a 2 - 2 1/4 inch drywall screw into a variable speed drill. Thread the bullet onto the drywall screw.

    Use polishing compound because it removes material much slower than valve grinding compound and is more forgiving and easier to clean up.


    Put a light coating of polishing compound evenly all over the bullet and close your mold around the bullet. Run the drill very slowly to get the bullet to seat properly into the grooves of the mold.

    Once set slowly start the drill, using very light pressure on the mold handles. After a minute or so the bullet will be seated perfectly and you can add more compound.

    After a couple of minutes of lapping, you will need to clean the mold really good and cast a couple of bullets and check the diameter. You may have to do this three or four times, but it is better than ruining the mold.


    You should not try to remove more than .002 - .003 in this manner using a hand drill. If more material is removed errors can start creeping into the mold, so if necessary proceed at your own risk.

    If there is any indication that out of roundness is happening you should stop right there. This occurs at the base of the bullet first. You should also add polishing compound for every minute of lapping.
    It's tedius to do but if you do it right the bullets come out better than before lapping. Just take your time and check your work very often and it will turn out fine.

    I learned this the hard way and had to replace a couple of molds before I got smart about checking my work often.

    Use this method to polish new molds without removing any significant amount of material. Bullets from a mold treated like this are less prone to sticking in the mold. They have a very smooth overall appearance with no machining marks evident.

    You can also lap a sizer die using this same method. Lee sizers also only go up to .457. Mine sizes .459 with #2 alloy now and is perfectly round. It takes a bit longer but it works. PC
    BOT GBUSA, Charter member team 444.
    Life member NRA, Life member WAC.

  2. #2
    Gunfighter
    Join Date
    Mar 2004
    Location
    Here
    Posts
    957
    Member #
    390
    Thanked
    1 times

    Re: LAP A BULLET MOLD & SIZER TO INCREASE SIZE

    Yup, you sure can mess up moulds using power tools. That's why I do it by hand. Same method of fitting a centered shank to a bullet from that mould, but I have a drill chuck on a handle I hand turn. A spare chuck would do. Fine valve grinding coumpound works fine for me because the bullet is not being turned as fast. I do have a set of Clover Compound in a range of grits for when I just want to polish or remove a very little metal. The advantage to doing it by hand is feel. I can tell when I'm getting out of line.

    With the Lee sizers, the easy way is to lube up some cull bullets compound, and shuck them on through like you were sizing them normally. I've lapped a few Lymans in a lathe, but find that more difficult and a limit of about .002 lapping without having to make a new internal rod.
    hen you hear hoofbeats, look for horses, not zebras.

  3. #3
    Really Short Fuse Administrator
    Join Date
    Mar 2004
    Location
    Edmond, Oklahoma - That's just North of the Red River Team .444 Charter Member
    Posts
    14,843
    Member #
    72
    Thanked
    278 times

    Re: LAP A BULLET MOLD & SIZER TO INCREASE SIZE

    I use dishwashing soap for a lubricant while lapping. I started out with great trepidation but it was easy and I just took my time and timed the amount of lapping time for each cavity. I also used fresh polishing compound and lubricant each time I lapped after washing out the last batch. I think I spent about an hour doing the job.

    Dave
    http://smg.photobucket.com/albums/v354/vtdw1/
    MO Member #77

  4. #4
    Esteemed Sharpshooter
    Join Date
    Jan 2008
    Posts
    9,664
    Member #
    4690
    Thanked
    458 times

    Re: LAP A BULLET MOLD & SIZER TO INCREASE SIZE

    I just special ordered a .461" mold from Lee precision and it was $25 + $4 shipping. They will make what you want. You just need to order it and wait for up to 4 to 6 weeks. Lee precision tools. Custom service.
    1-262-673-3075
    Life NRA
    USN-Iron Men on wooden Ships, minesweepers.
    MSO 488 and MSO437
    Team 45-70 #394
    Team 39 #96
    Team 60 #35
    Team Old Pharts #44 "Pharty-Four"
    Life member RMEF
    American Legion

  5. #5
    Tinhorn
    Join Date
    Nov 2007
    Location
    Eastern Washington
    Posts
    37
    Member #
    4280

    Re: LAP A BULLET MOLD & SIZER TO INCREASE SIZE

    Or just beagle it. Works for me and is reversible.

  6. #6
    Site Contributor Contributing Member
    Join Date
    Feb 2007
    Location
    Montana
    Posts
    539
    Member #
    3159
    Thanked
    89 times

    Re: LAP A BULLET MOLD & SIZER TO INCREASE SIZE

    Quote Originally Posted by truckmsl
    Or just beagle it. Works for me and is reversible.
    Can you please explain "Beagling" or provide a link?
    ..

  7. #7
    Really Short Fuse Administrator
    Join Date
    Mar 2004
    Location
    Edmond, Oklahoma - That's just North of the Red River Team .444 Charter Member
    Posts
    14,843
    Member #
    72
    Thanked
    278 times

    Re: LAP A BULLET MOLD & SIZER TO INCREASE SIZE

    It is placing something (usually aluminum tape) between the mold halves which enlarges the cavity. I do not care for it as you can get fins as well as out of round boolits quite easily.

    Dave
    http://smg.photobucket.com/albums/v354/vtdw1/
    MO Member #77

  8. #8
    Deadeye
    Join Date
    Oct 2008
    Location
    Arequipa, Peru
    Posts
    562
    Member #
    6862
    Thanked
    72 times

    Re: LAP A BULLET MOLD & SIZER TO INCREASE SIZE

    Good morning Lapping molds is as easy as lapping any metal object. It sure is easier than typing !
    Remove cut off plate. Plate 1/4 -20 nut centered over the mold cavicty. With HOT WW pour Bullet. Let cool and drop your lapping tool. Let mould cool or cool it slowly with water well away from the hot lead. Spread well watered lapping compound onto the bullet area you want to enlarge ... maybe it is the whole bullet or just the nose.. base... Insert lap bullet into mold. Be sure the mold blocks are COMPLETLY closed. I place mine into a padded vise. With a 1/4 box wrench or small socket rotate the lap a few times. If you feel very lottle resistamce add just a small bit of lap coumpound. You will get a feel for it. Wet is goood ! Rotating the lap 50 times MAY add about .0005- .001 to an iron mould. Aluminum cuts much faster. Trial and error is the only route there is. All molds are different in diameter and material. Clean mold and cast a buulet of the mix you want the bullet made off. Measure...
    Depending how much I need to open the mold I may need to repete the process 2-5 times.
    But I open molds for shooting OLD firearms and have no regrets. Most molds today are made for WW so PURE lead casts way small... but not on my molds.
    Mike in Peru
    Mike in Peru God Bless you.

  9. #9
    Esteemed Sharpshooter
    Join Date
    Jan 2008
    Posts
    9,664
    Member #
    4690
    Thanked
    458 times

    Re: LAP A BULLET MOLD & SIZER TO INCREASE SIZE

    I would be careful about cooling molds with water. As a matter of fact I would not do it at all and especially with iron so as not to warp the blocks or rust, not to mention the safety factor. Myself, if I do not have time to wait for cooling I will save for another day as casting equipment is very expensive and some of my molds are old timer molds and hard to replace.

    Joe
    Life NRA
    USN-Iron Men on wooden Ships, minesweepers.
    MSO 488 and MSO437
    Team 45-70 #394
    Team 39 #96
    Team 60 #35
    Team Old Pharts #44 "Pharty-Four"
    Life member RMEF
    American Legion


Home | Forum | Active Topics | What's New | Subscribed Threads

Links

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts

Search tags for this page

bullet mold lapping
,
bullet mould enlarging
,
enlarging a bullet mould
,
how to beagle a mold
,
how to enlarge a bullet mold
,
how to enlarge bullet mould
,
how to polish bullet molds
,
increasing the size of a bullet mold
,
lap bullet mould 1000 grit
,
lap lee mold
,

lapping a bullet mold

,

lapping bullet mold

,
lapping bullet molds
Click on a term to search for related topics.