Inline FabricationMidSouth Shooters SupplyBallisti-CastStainLess Steel Media
Graf & SonsRotoMetals2Lee PrecisionTitan Reloading
Results 1 to 13 of 13

Thread: J-word vs Lead boolit powder charge questions.

  1. #1
    Boolit Master

    Lights's Avatar
    Join Date
    May 2012
    Location
    MN USA
    Posts
    317

    J-word vs Lead boolit powder charge questions.

    Ok I have been reloading for a long time but just recently got into casting for my 9mm and 45acp. I have three loading manuals here and they all state lower powder charges for cast boolits than J-word bullets. This does not make sense to me. It would seem to me that a J-word bullet would create more pressure to swage into the bore than a cast boolit because of the copper jacket being harder than lead. Am I wrong? So my real question is, why is it that load data for cast boolits have published lower powder charges than there J-word equivalent?

    Thanks,
    Mark
    NRA Life Member
    OGC Member
    USPSA Member

    When the people fear the government, there is tyranny. When the government fears the people, there is liberty.
    Thomas Jefferson


  2. #2
    Boolit Master

    Join Date
    May 2013
    Location
    michigan
    Posts
    504
    Mainly because lead has a lower coeficent of friction than gliding metal used for jackets. The lead will slide easier down the barrel than the gliding metal jacket.
    "Beer is proof that God loves us and wants us to be happy".
    Ben Franklin

  3. #3
    Boolit Master

    Lights's Avatar
    Join Date
    May 2012
    Location
    MN USA
    Posts
    317
    Quote Originally Posted by Zymurgy50 View Post
    Mainly because lead has a lower coeficent of friction than gliding metal used for jackets. The lead will slide easier down the barrel than the gliding metal jacket.
    So if that is true. Shouldn't you be able to put a larger powder charge behind a lead boolit?
    NRA Life Member
    OGC Member
    USPSA Member

    When the people fear the government, there is tyranny. When the government fears the people, there is liberty.
    Thomas Jefferson


  4. #4
    Boolit Master
    bigted's Avatar
    Join Date
    Mar 2009
    Location
    Sweet Home Oregon
    Posts
    2,935
    you answered your own question LIGHTS. it be the pressure thing. it takes more power to push jacketed then a lead boolit. also takes ...[in some cases]... less power to push a lubed paperpatched boolit then a bare lead boolit.

    so the powder requirement in a row from most needed to least is;

    1- jacketed
    2- lead
    3- lubed paperpatched

    also you will notice that the powder speed is usually different in these applications. some powders interchange nicely such as the IMR3031 and 4064 and the RL-7 powders as well as unique.
    WHEN ALL IS SAID AND DONE...MORE WILL BE SAID THEN DONE

  5. #5
    Boolit Master

    Lights's Avatar
    Join Date
    May 2012
    Location
    MN USA
    Posts
    317
    OK, I understand that and that is exactly what I was thinking. I have been comparing apples to apples as far as powder and bullet weight. So most loading manuals are full of s^*t on their published max loads for lead boolits.
    NRA Life Member
    OGC Member
    USPSA Member

    When the people fear the government, there is tyranny. When the government fears the people, there is liberty.
    Thomas Jefferson


  6. #6
    Boolit Designer 45 2.1's Avatar
    Join Date
    Mar 2005
    Location
    Little Egypt, Part of the political fifedom of Chicago
    Posts
    7,416
    Quote Originally Posted by Lights View Post
    So most loading manuals are full of s^*t on their published max loads for lead boolits.
    Give the man a cigar............
    45 2.1

    Knowledge without understanding is a dangerous thing. For a little knowledge entices us to walk its path, a bit more provides the foundation on which we take our stand, and a sufficient amount can erect a wall of knowledge around us, trapping us in our own ignorance.

    Never sleep, never die

    Knowledge is easy to get, but worthless if you never use it. However the info is free, so the only person you have to blame is yourself if you chose not to use the information.

  7. #7
    Boolit Master
    lylejb's Avatar
    Join Date
    Jun 2009
    Location
    canby, or
    Posts
    989
    So most loading manuals are full of s^*t on their published max loads for lead boolits.
    Pressure and velocity are two different things, and not as linear a relationship as we might think.

    While it's often true that the many published cast loads are not at SAAMI max pressure, they might be at a velocity limit for THEIR bullet. I'm thinking about some of the soft swedged bullets Speer and Hornady made. Their bullet alloy, hardness, fit, and lube are likely not the same as your home cast boolits.

    If their bullet becomes inaccurate, leads, or otherwise performs poorly above XXX velocity, there's no reason for them to publish a load for that.
    NRA life member

    LB

  8. #8
    Boolit Master

    Join Date
    May 2013
    Location
    michigan
    Posts
    504
    Most reloading manuals stop lead bullet testing when groups start to open up, or they start to get leading. Yes, you can drive a pure lead slug at 1800fps out of your 357 revolver. the question is: do you really want to?
    "Beer is proof that God loves us and wants us to be happy".
    Ben Franklin

  9. #9
    Moderator


    runfiverun's Avatar
    Join Date
    Dec 2007
    Location
    soda springs Id.
    Posts
    20,892
    sides that how many bullets are you gonna sell if the home made ones make them look bad by producing higher velocity's [velocity sells product]
    it's all an educated guess,,,, till the trigger is pulled.

    the more i find out about shootin boolits, the more it contradicts everything i ever learned about shooting jaxketed.

  10. #10
    Boolit Master



    Join Date
    Dec 2012
    Location
    Warren Co., Va.
    Posts
    1,855
    Quote Originally Posted by Zymurgy50 View Post
    Most reloading manuals stop lead bullet testing when groups start to open up, or they start to get leading. Yes, you can drive a pure lead slug at 1800fps out of your 357 revolver. the question is: do you really want to?
    That's not a good comparison, as the scenario is so far fetched. The point he is making is that if 'X' amount of powder 'Y' is the proper load for a 200gr j-bo in a .45acp, then why wouldn't that same load be appropriate for a boolit? I use the j-bo chart for my lead slugs in various pistols, and have had no problems with accuracy, feeding, and NO signs of overpressure. Of course, these are all modern guns made of modern steel. I would not do this in one of my turn of the 20th century top break revolters. And in rifles, that is a whole nother question. But with pistols, yeah, it's okay.

  11. #11
    Banned


    Bret4207's Avatar
    Join Date
    Mar 2005
    Location
    St Lawrence Valley, NY
    Posts
    20,012
    Quote Originally Posted by Lights View Post
    OK, I understand that and that is exactly what I was thinking. I have been comparing apples to apples as far as powder and bullet weight. So most loading manuals are full of s^*t on their published max loads for lead boolits.
    Well, yeah, sorta. Thing is the faster you push cast the more important all the little factors become. Fit, dynamic fit, at 750 or 850 or 1500 fps is different than at 900, 1050 or 2500. Sometimes bad things, real bad things happen when you decide to push that boolit out with a whole big ol' bunch o'powder. So, if you want to pick the pace up move slowly and OBSERVE what happens. Write it down and when you start changing things like luube, diamter, alloy, BHN, seating depth, etc. only change one thing at a time. Sometimes you get real lucky and your chosen gun/boolit/powder mix works just dandy, other times you spend a lot of time with a cleaning rod and 4/0 steel wool cleaning that sewer pipe full of lead that used to be a nice, clean barrel.

  12. #12
    Boolit Master
    Join Date
    Jul 2012
    Location
    Southern Utah Desert
    Posts
    245
    Anyone posting here ever do A/B testing of similar-weight and shape boolits and J-Words which included velocities?

    Back when avoiding a kB! event in .40 S&W pistols was a great concern, I studied the Winchester reloading guide in some detail because it was one of the few that included pressures in the tables of data and estimated velocities for their loads.

    What I found was that, leaving out obviously "short range" mouse phart loads, the W-W published max charges using the same powder and jacketed and lead bullets of the same weight, there were differences in charges, in a range of up to either 5 or 7% lower for lead getting almost identical velocity, on down to a minimum of zero (identical max charges, though the velocities were a little bit different if charges were identical or .1 gr different.

    I also concluded that seeing a "max" load's PRESSURE for one bullet being a few thousand PSI or CUP lower than the other near-identical weight bullet might be because other variables between the two bullets made one more likely to "spike" the pressure or become inconsistent at only .1 gr more.

    So I'd be careful with the rules suggested above.

  13. #13
    Boolit Master
    Join Date
    Aug 2012
    Posts
    2,043
    I re-read the OP a couple of times to try to figure out what the point was and I still don't know for sure. I just looked at 45 ACP data in a Lyman manual and I don't see the discrepancy as portrayed in the OP. Am I missing something?

    200 gr Jacketed
    BE, 3.4 gr, 604 fps, 7100 CUP..........BE, 5.7 gr, 942 fps, 17800 CUP

    200 gr Cast
    BE, 3.5 gr, 645 fps, 6900 CUP..........BE, 5.6 gr, 869 fps, 15700 CUP

    --------------------------------------------------------------------------------------

    200 gr Jacketed
    700X, 3.3 gr, 597 fps, 7400 CUP.....700X, 4.9 gr, 871 fps, 17300 CUP

    200 gr Cast
    700X, 4.0 gr, 745 fps, 10300 CUP...700X, 5.2 gr, 940 fps, 17300 CUP

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