Turning my own Solid Brass bore riders For the 338 Lapua

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by Alaskan338Lapua, Jun 10, 2009.

  1. Alaskan338Lapua

    Alaskan338Lapua Active Member

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    I was looking through the harbor frieght tools catalog the other day and I saw a micro lathe for $300. I was almost instantley reminded of how Lehigh bullets wants $50 some dollars for a box of 50 338 projectiles. Has anyone ever attempted to turn thier own bullets out of solid brass or copper stock. I would imagine one could invest in a box of bullets and then just copy the dimensions. but somehow I see a ruined 27'' schneider barrel in my future. Any thoughts? I am a competent person, but alas I'm no gunsmith/machineist.
     
  2. noel carlson

    noel carlson Well-Known Member

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    AL,

    If you are competent at basic machine work (holding tolerances), there should be no fear of ruining a barrel.

    A true "bore-rider" will require a purpose specific chamber however, and recalibrated bourrelet dimensions to accomodate throat wear.

    The brass alloy which you will most likely come across is C-360. This has a very high zinc content (~35%), and does not act particularly well as a bearing material. It will tend to "plate-out" in the bore... but it is common, and inexpensive. If you move up to a bronze, or copper alloy, you will rapidly appreciate the material cost.

    Have fun.

    Best,
    Noel
     

  3. Alaskan338Lapua

    Alaskan338Lapua Active Member

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    Great reply! It sounds like you have experiance turning solid bullets and machineing. have you personally turned any bullets for personal use? If so a few pictures would be great. I am curious at how I would turn an ogive. Correct me If I am wrong but there are ways to set a lathe to make tapered cuts right? It seems that short of buying a CNC machine the size or a semi that turning consistant ogives would be a pretty major task.
     
  4. vintec

    vintec Well-Known Member

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    The $300.00 would best be used buying the bullets from Lehigh.

    My brother bought one of the harbor freigt lathes at a yard sale one time for $100.00 he brought back here to my shop set it up beside my Okuma CNC lathe, he said we could use it for something and that it was only $100.00. It works ok to put small stuff in maybe to run some emory cloth on. But it will not accuratley cut anything....anything. It will just barley turn aluminum.

    To actully produce a bullet on a manual lathe with a radius ogive would be very difficult, and very time comsuming. You can cut a taper with a manual lathe but requires, a compond ,or a taper attachment, or off setting the tail stock. None of them would be an econonmcal choice to make bullets.

    But it if you wanting to machine something just as a hobby dont waste your time or money on one of the Harbor Friegt machines. The will never be able to produce a good quality part, in a timely manner..... or maybe at all
     
  5. Alaskan338Lapua

    Alaskan338Lapua Active Member

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    Ok good to know thanks for the info. Harbor frieght dosen't have a forum so I can't just go on and ask these sort of questions. I have never priced CNC lathes. What kind of $$$ and I looking at? Then you have to have a computer to program it all and I imagine a degree to go with it. besides that could someone post a list of the solid bullet manufacturers so we could all go and have a look.
     
  6. noel carlson

    noel carlson Well-Known Member

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    AL,

    Unless you are approaching this from a purely recreational perspective, the investment is significant.

    If you examine the nose, and tail, of a Barnes solid, you will see that they are not point turned (and are realtively crude). The precise cutting is on the body only. This forming method could be adapted economically to a home/hobbiest environment.

    Swiss lathes are great. They only make sense for mass production of a single part profile however, and the cams alone will cost ~$800 per set-up. CNC is versatile, but definitely not a "hobby" level investment.

    Yes, I do cut bullets. There are controlled expansion test results, of a hunt version, which you will see shortly in a report at this site. Photos of some of the earlier prototypes are in multiple threads at Sniper's Hide. They are an engraving-band configuration, which is quite different than the bore-rider concept.

    Best,
    Noel
     
  7. davewilson

    davewilson Well-Known Member

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    Noel, my understanding of the term "band" when used with bullets meant it was a borerider (GS Custom). full diameter bullets were referred to as a "groove" design (Barnes).what am i missing?any plans for a 338 10 twist hunting bullet?
     
  8. noel carlson

    noel carlson Well-Known Member

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    Hello Dave,

    Drawings would really help here, but I will try to make the distinctions by referencing well known projectiles.

    All bore-riders have drive bands (usually one), but not all "banded" bullets are bore-riders.

    The typical artillery projectile is a bore-rider. It has a forward, sub-bore diameter quasi-band known as a bourrelet, which fits as snugly as possible to prevent in-bore cant, followed by a supra-groove diameter "drive band" which serves the dual purpose of a gas check, and imparting spin. Many of the recent 50 caliber competition projectiles fall into this category.

    GS Custom projectiles are not bore-riders. They "engrave" the full length of the body with a full-bore diameter shaft, and seal with 5-6 supra-groove diameter bands. Strictly speaking, the bands in this application, are neither exclusively "drive" nor "engraving" in function. They primarily seal, and simply aid in transferring spin. GS Custom is responsible, however, for a huge innovation in band design which does have a purely "drive" purpose. Variable width, and spacing lay-out, of the bands allow the use of a gain-twist rifling geometry, which is critical in generating the high spin rates required for 6.5+ caliber projectiles. In this application, either the forward, or rear, bands are side swaged during barrel transit, leaving a single primary band intact as a gas seal. The reason GS Custom does not use this to any great extent yet, is the scarcity of LGT, EGT, or VGT geometry barrels. Gerard's basic "type" is a hybird design, meant to accomodate the greater manufacturing tolerances of factory barrels.

    "Full-diameter" bullets have no bands but seal, and spin as the name suggests, by having a supra-groove diameter body. All jacketed bullets, and some solids like the original Lost River, fall into this category (although there is an interesting history on how this eventually became a sub-groove diameter projectile). Radial grooves are found on some varieties presumably to reduce friction. With imagination these structures create "drive bands", but the intent of the designer to patch a basic design flaw is usually transparent. Full-diameter solid projectiles are a bad idea in terms of both friction, and fouling.

    My projectiles fall into a pure "engraving-band" class which has it's roots in WWI artillery projectiles produced in Germany. The Paris Gun had two engraving bands, but some smaller calibers had up to six. In this configuration, the projectile body never comes into contact with the bore. Alignment, spin, and sealing all take place within the major, and minor, band diameters. What distinguishes the ZA projectile, is the inclusion of Gerard Schultz's sacrificial band concept, and use of drag minimizing formulas to generate nose and tail profiles.

    There is a 6.0 caliber ZA338 hunt projectile which will stabilize from a 1: 10" twist. It will be publicly available in 2-3 months. Contact me if you are interested.

    Best,
    Noel