Do FMJHP's expand?

Discussion in 'Caliber Corner' started by Sgt.K, Nov 14, 2012.

  1. Sgt.K

    Sgt.K They Just Work!

    Just wondering if .223/5.56 full metal jacket hollow points in either 55 or 62 grain actually expand as, I imagine, a semi jacketed would?

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  2. SCmasterblaster

    Millennium Member

    have a sizable cavity. And at the high speeds they operate, bullet expansion is very likely. :cool:

  3. Rifle JHPs don't expand like pistol rounds do, they fragment. All the hollow point does is (supposedly?) aid accuracy and tendency to yaw (which causes fragmentation).

    Jacketed Soft Points (JSPs) expand though. I don't hear them referred to as "semi-jacketed" much.
    #3 cowboy1964, Nov 14, 2012
    Last edited: Nov 14, 2012
  4. FMJHP is kind of an oximoron. The open tipped match type bullet can expand but can also pencil thru or fragment. Why they are not the best choice to hunt with in most calibers. A true JHP rifle bullet can certainly expand properly if designed to do so.
  5. SCmasterblaster

    Millennium Member

    how very interesting . . . . .
  6. CanyonMan

    CanyonMan In The Saddle

    Hey my friend ! Hope all is well !

    Your post here ?...... :thumbsup:

    Stat safe amigo !

  7. SCmasterblaster

    Millennium Member

    Do ammo makers offer .308Win with hollow point bullets?
  8. RWBlue

    RWBlue Mr. CISSP, CISA

    Federal match ammo comes to mind.
  9. SCmasterblaster

    Millennium Member

  10. The .308 bullet (7.62x51) is one of the few calibers the military openly issued hollow points to.
  11. Zombie Steve

    Zombie Steve Decap Pin Killa

    The thin drawn jacket on most open tip match (hollow point bullets) lends itself to fragmentation. While I think they work better on soft targets than fmj, they are designed for flight and flight alone. They just have to punch a hole in paper or make steel ring. The hollow cavity in the tip is to move the center of gravity back on the bullet and help stabilization in flight. If you want expansion, get a hunting bullet. Soft point, partition / A-frame, or something bonded like the accubond or deep curl.
  12. This is true. The bullet yaws and fragments much like the M193 style bullets of the 5.56mm (which is actually true for any pointed bullet with somewhat fragile construction).

    They are much more effective than FMJ bullets against unarmored targets.
  13. SCmasterblaster

    Millennium Member

    I agree, brother! Good description.
  14. WiskyT

    WiskyT Malcontent

    According to my old Hornady manual, the BTHP match bullets, Hornady's anyway. are made that way for two reasons. The HP makes the bullet longer for a given weight which increases the bearing surface. Also, the HP allows the base to be closed which means it's more uniform. A uniform base is critical to accuracy.

    As for expansion, the match type bullets, according to Hornady, are not to be used for game as there performance can't be predicted. The Sierra BTHP match bullets apparently are destructive and are used by the military for this purpose with a nod and a wink in addition to their accuracy.

    There are HP varmint bullets. They are designed to basically disintegrate on impact to minimize downrange hazards. Some of them are so fragile that they will fly apart in flight if they are shot too fast through a too high rate of twist barrel.
  15. WiskyT

    WiskyT Malcontent

    Also, there are/were some combloc steel jacketed HP rounds sold cheap at one time. They looked like they would be good expanders, but apparently some of them acted just like ball ammo.

    Overall, you need to see what a specific bullet was designed for. The bullet/ammo companies make the bullets/ammo for specific purposes.
  16. SCmasterblaster

    Millennium Member

    I had forgotten all about that - the fact that HP or SP bullet have enclosed bases.

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