5.7x28mm Terminal Ballistics

Discussion in 'Ammunition and Reloading' started by ministerofdeath, Mar 28, 2008.

  1. Syntax360

    Syntax360 Moderator

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    Re: MSAR STG-556

    Isn't an issue? Penetration is THE issue with the 5.7, even in SS190 trim... As far as the lethality of the round, countless law enforcement agencies have dropped the weapon system after it has proven ineffective. Everyone wanted this weapon system to live up to all the hype the FN junkies created, but it simply lacks substance. Fired out of either weapon system in any of the commercial or LEO-only loads, the 5.7 lacks the penetration and expansion of standard subgun calibers and lacks the energy of a full blow 5.56 or other rifle caliber... Simply put, it was a really cool looking, really hyped failure.

    I've followed quite a few of your posts, ministerofdeath, and you absolutely have your terminal ballistic "priorities" bass-ackwards. Energy is great, but ONLY when it compliments adequate penetration. Energy scores a DISTANT second to penetration when ranking performance of defensive ammunition.

    I'm not saying this weapon system has no application - if a small PDW with the ability to lay down crazy suppressive fire is required, the P90 fits the bill (and god knows it beats out HK's failed 4.7mm :lol:). In the hands of very skilled operaters (as is the case with the Secret Service), the quality of shooter is going to make up for the weapon system's shortcomings... But at the end of the day, trying to liken the 5.7x28mm to a viable replacement for the 9mm-.45ACP, .223, or any other "real" caliber is a losing proposition - the numbers simply do not add up.

    And what a tangent we have taken this thread on... We started out talking about the MSAR and stumbled into the dark, chimeric world of FN and now onto discussion about a cartridge that no MSAR has (or will be) chambered in... :lol: A new thread would probably be prudent if you guys wish to discuss all this business in further detail... :beer:
     

  2. Syntax360

    Syntax360 Moderator

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    Hold up there, sunshine... I didn't "personally insult" you - I said you thought process is wrong. You give velocity too much credit...

    That isn't how it works, ESPECIALLY with small, light projectiles. When you start juping up small hunks of metal to blaze through the air at incredible speeds and then smash them into fluid environments, they come apart. This is why you can't take any old 115gr. 9mm, load it up to +P+ pressures, and expect it to hold together long enough to out-penetrate a much slower 147gr., etc. We see the same thing happening with 5.56 in various loads (not just the M193/M855 that are designed to fragment)...
     
  3. Buzz

    Buzz Premium Member

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    I think that calling the PS90 a "failure" is open to question. The gun with the SS190 did exactly what it was designed to do. It provided a PDW for behind the lines support that could defeat Russian body armor. That "D" in "PDW" stands for defense, and that was the purpose of the weapon. It was never intended to be an offensive weapon.

    My understanding is that the gun got caught up in a lot of NATO politics and the need for the gun fell with the Wall. The reputation of the SS190 got hyped and politicized and the controversy began. The watered down civilian rounds pulls most of the teeth from the PS90, but I think it is useful to remember that the 5.7 round is only in its infancy and that the limited ammo availablity, controlled by FN, is a temporary situation, especially with reloading. For me the jury is still out.

    I have to laugh about the 5.7. Depending on who is arguing it can be everything from a mankiller to a plinker, or an over-penetrator or one that will not penetrate enough. Some say that it tumbles, others that it yaws, and ballistic tests seem to get ignored. While I'm not convinced one way or the other, it seems to me that the two available rounds offers a basis a good bit shy of that necessary of coming to anywhere near a final verdict. Of course the government may end up stepping in and settling that for us once and for all, and at that point the PS90 will go from controversial to legendary.

    To me the bottom line is that folks are arguing about a gun that is no longer being used for its intended purpose and judging it on a basis that has little overlap with reality. The 5.7 may well develop into a round that will bring the PS90 gun more uses, but for now it's more of a novelty.

    Then again, take a Beretta CX4 in 9mm, or an HK94 (both semi-auto 9mm carbines, the round the 5.7 was to replace) and then add in a PS90. Say you have to take out an opponent at 200 yards. Chose your weapon.

    Buzz
     
  4. MrApathy

    MrApathy New Member

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    interesting arguments but lacks substance.

    velocity fps. energy in ft lbs. bullet weight . velocity drop off per yards.

    5.7mm=.224" diameter.

    223 remington is know well for penetration but the damage is not always effective with 1 shot.
    it comes down to shot placement for rounds like 5.7x28mm and 223remington.

    whats the bullet weight variance for 5.7x28mm?

    its a round due to politcal correctness will most likely never see restrictions eased short of a war on US soil

    quick look at midwayusa.com the ammunition there in 5.7x28mm have bullet weights of 28.5 gr and 40gr.

    FN SS195LF Ammunition 5.7x28mm FN 28.5 Grain Lead-Free Spitzer
    2133fps 288ft lbs energy muzzle

    FN SS197SR Ammunition 5.7x28mm FN 40 Grain Hornady V-Max
    2034fps 367ft lbs energy muzzle

    feel free to go to handloads.com and test the ballistics out
    http://www.handloads.com/calc/

    recommend setting yard interval to 5

    try .355 147gr round nose/JHP or boattail with velocity of 1100fps
    also try .355 90gr any bullet type with velocity of 1500fps
    9mm can send 147gr bullet 1100fps with 4" barrel could do it faster with +p loads
    90gr 1500 fps short bullet so limited to COL can probably send it faster without increasing barrel length.

    what would you rather count on a 28.5/40gr bullet or something 2 to 3 times that.
    its much like a 5.56 vs 7.62x51 or 223rem vs 308win
    sure you can shoot 5.56/223 rem 1000 yards its not going to be anywhere near as effective as 308win which can use bullets 2x-3x heavier.

    penetration is one thing critical damage that doesnt close back up is another.

    I dont totally agree with what syntax and Buzz have said but I believe they are along the lines of reality of the effectiveness of 5.7x28mm otherwise we would see the cartridge take off.

    try looking up the cartridge .224BOZ another is 224VOB

    5.7x28mm color me unimpressed. its not a good defensive round it was designed to penetrate armor.
    niche cartridge for limited uses.
     
  5. Buzz

    Buzz Premium Member

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    And that's exactly it, at 200 yards, or 150, or 100 for that matter, I'd rather have the PS90 than a 9mm carbine because of the ability to achieve that shot placement and quick follow-up shots back on target with a minimum of muzzle rise. The gun in the right hands could be devastating even with the toothless civie rounds. Add to that the 50 round capacity, and the gun is potentially more effective than other carbines that get a lot more respect.

    The gun is all about shot placement and the ability to put multiple rounds on target very quickly and accurately.

    Yeah, politics have arguably neutered the round but we're really only a couple years out and I think it remains to be seen what can be and will be done with reloaded rounds.

    Buzz
     
  6. Syntax360

    Syntax360 Moderator

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    The biggest (and probably most obvious) problem with the 5.7x28mm is that it is a small projectile moving at relatively low velocities. Primary cavity size will not lend much to causing incapacitation from blood loss and we're certainly not moving fast enough for hydrostatic shock to contribute much to the wound characteristics (in FiveseveN, P90, OR PS90 trim).

    I thought add some words from a few people who probably are more qualified to talk about this subject than most of us...

    Dr. Gary Roberts had this to say about the 5.7x28mm & P90 weapon system:
    As Buzz mentioned, this round has inspired an incredible amount of debate. Purely speculative, but one has to wonder why FN hasn't pursued any 3rd party testing to settle the debate... any guesses why?

    A member of Jacksonville SWAT posted up over on lightfighter awhile back and had this to say about the 5.7:
    Renouned instructor Pat Rogers of E.A.G. Tactical had this to say:
     
  7. Buzz

    Buzz Premium Member

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    Hmmm, kinda makes you wonder why HK has developed the MP7 with the 4.6x30HK round, a somewhat faster round that is also lighter with less energy and surface area.

    Buzz
     
  8. Syntax360

    Syntax360 Moderator

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    If the 5.7 does one thing well, it is outperform the 4.6... As mentioned before - these are niche calibers and weapon systems primarily designed to defeat body armor and to be wielded by very capable shooters... CCW and home defense are certainly not what either platform was intended for and that is why there is a plethora of better choices available to us... :wink:
     
  9. Buzz

    Buzz Premium Member

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    Absolutely. I also know some folks who at the moment are in the midst of procurring an MP7 who will never shoot it other than for the pure fun of shooting such a weapon. To me there is great value in that.

    Buzz
     
  10. bigtaco

    bigtaco Active Member

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    i want an xm-8 chambered in something .260ish
     
  11. Buzz

    Buzz Premium Member

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    Question. Considering the physics/ballistics, is there a round in this caliber short of the SS190 (and other restricted loads) that would bring this caliber into an acceptable lethality range when all things are considered? Is the 5.7 a complete dead end, or is there still potential?

    Buzz
     
  12. Syntax360

    Syntax360 Moderator

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    :shock: An MP7? Stateside? Surely you jest... I assume these people are HK dealers or LEO types? At least FN will sell their whiz-bang gun to the civvie market - those snobs over at HK won't even give us a crack at it... :v
     
  13. Buzz

    Buzz Premium Member

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    Yup! There is a very good chance that I will get to shoot one sooner than later.

    Buzz
     
  14. Syntax360

    Syntax360 Moderator

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    It seems most of the evolution of the 5.7x28mm thus far has been to get away from the kevlar-punching hysteria created by the gun grabbers. While it certainly is possible that a new load could come along with totally different terminal ballistics, the 5.7 has a lot going against it - you would probably have to make it heavier and faster (even 40-50gr. 5.56 has serious penetration problems)... I doubt the niche market is going to forget about the 5.7 anytime soon, so I wouldn't abandon all hope...
     
  15. Buzz

    Buzz Premium Member

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    That was sort of my thought as well. I think I read somewhere that new loads for the 5.7 where in the works, possibly to boost the speed enough to make them frangible. I'm not sure whether that's possible, especially with the pistol.

    I also think that the MP7, whether available or not, will keep this style PDW very visible, although with its size the MP7 has some other things going for it.

    No matter, I still like the concept of being able to bring a lot of accurate fire onto a target and at greater ranges. If they can enlarge the wound cavity while excising the armor piercing capabilities they may have a winner.

    Buzz
     
  16. Buzz

    Buzz Premium Member

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    BTW, speaking of the 4.6x30HK round, the first HKP46 will hit the shores soon. I just hung up the phone with a friend exepecting the MP7 and he just placed an order for the P46. :shh:

    Buzz
     
  17. MrApathy

    MrApathy New Member

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    be nice if they had bolt actions and basic semiauto plinking rifles for it. bet its nice cartridge on varmints.
     
  18. Syntax360

    Syntax360 Moderator

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    The 5.7, 4.6, or both? I caught the 5.7 bug from one of my buddies until I did my homework, but IIRC there was a company developing a 5.7 bolt gun (I think it was the same people who designed the very ARish 5.7 rifle...). I'm sure you know HK does not sell the 4.6 (weapon system or round) to the civilian market and has expressed on numerous occasions that they have no intention to ever do so (the product of politics I guess :evil:)... I'll bet you're right, MrA - either round wound probably be awesome for critters! :twisted: