50 BMG Sabots

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by edge, Oct 4, 2006.

  1. edge

    edge Well-Known Member

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    I have a question for anyone that has used 50 BMG x 30 caliber sabots.

    I recently purchased almost a thousand sabots from a member here, thank you for the extremely fast mailing /ubbthreads/images/graemlins/smile.gif

    My question involves whether these things stay attached to the 30 caliber bullet all the way to the target, or if they separate?

    Since I am re-machining them for use in my .458 I have the opportunity to make changes and wonder how they work in general.

    My initial inspection of these are that they are not engineered for easy separation.

    1) The petals do not seem to be split far enough to the base to ensure that all petal shear cleanly and at the same point in relation to the bullet.

    2)The 0.308 diameter is grossly tapered at the base. It actually does not reach 0.308 for about .300 from the base of the bullet. I imagine that upon firing the bullet will be somewhat swaged into the base taper making separation inconsistent.

    3) The petal thickness varies by as much as 0.005 making run-out an issue.

    Has anyone that shoots these ever recovered any. If so do the petals shear cleanly and at the same point relative to the bullet?

    Any replies will be greatly appreciated.

    I have machined about a dozen and hope to test them this weekend. If i get a chance I will post a picture tonight or later.

    edge.
     
  2. Black Diamond 408

    Black Diamond 408 Well-Known Member

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    Edge,
    When i used them in my 50cal, i found them on the ground. I machined a few of them to try in the 408ct rifles but they were to thin. I never did check the internal specs, run out seems to be the biggest problem with any sabot. Let us know how they work.

    Dave
     

  3. edge

    edge Well-Known Member

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    A few of the sabots. The top cutaway is the straight 50 as purchased. The bottom cutaway is 0.458 with a groove cut to enhance petal breakage and separation, this may or may not be needed and will require a great deal of trial and error.
    Bullets are 150 grain SST's (0.308)

    [​IMG]


    edge.
     
  4. davewilson

    davewilson Well-Known Member

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    150's out of a 50? what powder are you plannin on burning here? did you consider extending those slots down closer to your groove? might help the separation process.
     
  5. edge

    edge Well-Known Member

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    I expect that the groove will end up at the base of the bullet and that the slots will be extended, but one step at a time. I would prefer to keep the machining to a minimum. These were 50 caliber sabots but I machined them on an arbor to fit my 0.458 barrel.

    These are considerably lighter than what I currently use which may add a few hundred fps to my current loads which just top 3k. 3200fps would be a good area as long as they can remain in the moa arena.

    edge.
     
  6. Guest

    Guest Guest

    [ QUOTE ]
    ...long as they can remain in the moa arena.
    edge.

    [/ QUOTE ]

    MOA, I'm trying to get under 3 MOA. My 50 BMG Sabots are at Here and And Here

    Where can I get 100 of your Sabot's?

    I had a 50 BMG made just to shoot Sabots (fast twist 9.5) - and sub-sonics.
     
  7. edge

    edge Well-Known Member

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    The sabots that I am working with are similar to yours, and I am machining them on a mandrel to straighten them out. This works because I am shooting them out of a 458 win mag barrel and not a .510 barrel.

    If you're only getting 3 moa accuracy then, IMO you need to see if the problem is the sabot or the powder/load.

    I would want to see you shoot through stiff paper or light cardboard at varying distances starting at about 5 yards, and every 5 yards until you see clear sabot and bullet holes. As an initial test you could just shoot through a bunch of boxes lined up in a row. Any recovered sabots should be inspected for damage.

    I suspect that you have a couple of degrees of bullet yaw and you need to know if the bullet/sabot combo is yawed at the muzzle or if this is happening during separation of the two components, or both ( very likely).

    I suspect that since these sabots are so short compared to a 750 grain bullet that they have a huge jump before they hit your lands and they maybe badly cocked prior to hitting the bore.

    The sabots that I have have petals that vary in thickness by several thousandths. For testing purposes you should measure them with a caliper and mark the high/low spots. Then hand feed the rounds so that the mark is always in the same spot. This will ensure that the CG jump at the muzzle is consistent from shot to shot instead of a random spot.

    edge.
     
  8. Guest

    Guest Guest

    I suspect your are right on all counts. My goal has always been 2 MOA.
     
  9. uncleB

    uncleB Well-Known Member

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    edge & BigBore,
    I have read this thread and truly dont get it,why or what is the purpose of using sabots in a 50BMG or 458WM ?????????? not trying to be a smart A$$ just trying to gain knowledge on the subject.
    UB
     
  10. edge

    edge Well-Known Member

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    [ QUOTE ]
    edge & BigBore,
    I have read this thread and truly dont get it,why or what is the purpose of using sabots in a 50BMG or 458WM ?????????? not trying to be a smart A$$ just trying to gain knowledge on the subject.
    UB

    [/ QUOTE ]

    It makes for a nice varmint/deer rifle. Flatter than a 30-06 and it does not beat the heck out of you. I have not tried it @ 1000 yards, but I could....still over 1200 fps at 1k.

    edge.
     
  11. Guest

    Guest Guest

    I'm doing it to punch thru more armour (not hunting). Perhaps some rock busting. Mostly science experiments.

    Remember how GG punched thru your armour with the wimpy Lapua Scenar? Impulse my friend. With a 155gr Scenar going 4,400 fps - I'll be able to do more damage than GG. My 150gr AP will do even better.
     
  12. uncleB

    uncleB Well-Known Member

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    [ QUOTE ]
    I'm doing it to punch thru more armour (not hunting). Perhaps some rock busting. Mostly science experiments.

    Remember how GG punched thru your armour with the wimpy Lapua Scenar? Impulse my friend. With a 155gr Scenar going 4,400 fps - I'll be able to do more damage than GG. My 150gr AP will do even better.

    [/ QUOTE ]
    now I understand, thanks for the post.
    UB
     
  13. Gargoyle

    Gargoyle New Member

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    I am looking for anyone that sells the .30 to .50 cal BMG Sabots. Does any one know who is selling them?
     
  14. nfhjr62

    nfhjr62 Well-Known Member

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    Question: what MV are you expecting with this setup