posted 11-17-2001 20:00            

Would you please expound on the following:
What is the wound ballistic potential of the Russian(Soviet) 5.45 round as used in the AK variants?
How does it compare (wound profile) to current and former mil. ball ammunition?
As provided in your previous information, you give good marks to synthetic “Ballistic Tip” ammunition for antipersonnel usage. Does this follow through with any currently produced 5.56/.223 loadings?

Current agency protocol calls for Federal “Tactical” .223 as the standard load for all ARs in vehicles, and changed out (when time allows) to 55gr FMJ for inside work. The rationale for this protocol is to obtain the best obstacle penetration (vehicle windows, etc) in the usual outdoor environment, and to obtain the most frangibility (through intervening walls/construction) during indoor operations. Is this reasonable? If not, would you suggest a better alternative (aside from hitting what we aim at) within the confines of the caliber?

posted 11-23-2001 04:40            

The 7.62 x 39 mm Russian M43 Type PS 120.5 gr FMJ boat-tail bullet which has a copper-plated steel jacket covering a large steel core and a typical muzzle velocity of 2340 f/s. In tissue, it typically travels approximately 9.8 to 10.6" point forward before beginning significant yaw. Most uncomplicated wounds of the torso and extremities have small punctate entrance and exit wounds and exhibit minimal internal tissue disruption since the bullet does not deform or fragment and usually exits before yaw occurs. Total penetration is around 29.1”.

The 5.45 x 39 mm Russian M74 53 gr FMJ boat-tailed bullet has a copper-plated steel jacket surrounding an unhardened steel core and a small 5 mm long empty air-space under the bullet nose. Its typical muzzle velocity is 3066 f/s. In contrast to the older 7.62 x 39 mm Russian M43 Type PS which it replaced, the 5.45 x 39 mm M74 53 gr FMJ commonly exhibits very early yaw in tissue, at approximately 2.75", but no deformation or fragmentation. In both uncomplicated extremity and torso wounds, the very early yaw allows the bullet to travel sideways through the body, increasing permanent tissue destruction and temporary cavitation effects. A small punctate entrance wound is present and the exit wound may be punctate, oblong, or stellate depending on the bullet yaw angle on exit. Penetration is approximately 21.6”.

As an aside, early yaw, similar to that exhibited by the 5.45 x 39 mm Russian M74 53 gr FMJ, is also produced with several other 7.62 x 39 mm FMJ bullets, including the:

--Yugoslavian M67 124 gr FMJ, flat based, copper-jacketed, lead core bullet which travels only 3.5" in tissue before yawing
--the U.S. commercially produced 7.62 x 39 mm 124 gr FMJ, copper-jacketed, lead core bullets which travel only 3.9" before yawing
--Chinese Norinco 7.62 x 39 mm 123 gr FMJ, copper-jacketed, lead core bullets which begin their yaw after only 2 to 2.5" of travel in tissue.

In both uncomplicated extremity and torso wounds, their very early yaw allows these bullets to travel sideways through the body, increasing permanent tissue destruction and temporary cavitation effects compared to the standard 7.62 x 39 mm Russian M43 Type PS 120.5 gr FMJ. A small punctate entrance wound is present and the exit wound may be punctate, oblong, or stellate depending on the bullet yaw angle on exit. Penetration of these bullets is around 24.4”.

The U.S. M855/Belgian SS109 62gr FMJ boat-tail bullet has a partial steel core surrounded by a copper jacket and a muzzle velocity from a 20" barrel of 3034 f/s. When fired from the 14.5" barrel M-4 carbine it has a muzzle velocity of approximately 2800 to 2900 f/s and when exiting the muzzle of the 10" barrel XM-177/Colt Commando and 8.3" barrel HK53, velocity is generally reduced to below 2500 f/s. Wound severity with this cartridge varies depending on bullet fragmentation. The degree of bullet fragmentation is related to impact velocity. At lower muzzle velocities and as the range to the target increases, the bullet striking velocity is reduced, limiting bullet fragmentation, and decreasing wound severity. Down to a velocity of approximately 2700 f/s, generally around 150 meters from a 20" barrel and 75 to 100 meters from a 14.5 or 16 inch barrel, the bullet enters the tissue, leaving a small punctate entrance wound, and then travels point forward for approximately 4.7". If the bullet leaves tissue at this point, it will leave a small punctate exit wound and will have caused minimal tissue disruption along the wound tract. If it continues to travel in tissue, it will yaw to 90 degrees at this point, flatten, and fracture at the cannelure (the knurled circumferential groove around the middle of the bullet into which the cartridge neck is crimped). The flattened bullet nose remains in one piece and retains 60% of the original bullet weight. The 40% of the bullet behind the cannelure shatters into many fragments that can spread up to 2.75" radially away from the wound tract. These fragment each cut their own path through the surrounding tissue, multiply perforating it. Temporary cavitation then exerts its stretch effects on this weakened tissue, synergistically increasing the permanent cavity by detaching tissue pieces. Wounds in body segments thicker than 4.7" show greatly enlarged permanent and temporary cavities and can create stellate exit wounds of 3.5 to 4.7" measured form the ends opposite the skin splits. At a velocity below 2700 f/s down to 2500 f/s, generally around 150 to 200 meters from a 20" barrel and 100 to 150 meters from a 14.5 or 16 inch barrel, the bullet yaws, breaks at the cannelure into two large pieces, but does not fragment, reducing the wound severity. Below 2500 f/s, generally beyond 200 meters from a 20" barrel, 150 meters from a 14.5 or 16 inch barrel, and at the muzzle of shorter barrels, the bullet remains generally intact and does not fracture or fragment, but does yaw and may exhibit some flattening of the base. This lack of fragmentation significantly decreases wound severity. Depending how early yaw begins, wounds may be similar to those produced by the 5.45 x 39 mm Russian M74 53 gr FMJ bullet. If the bullet passes through tissue before yawing, small punctate entrance and exit wounds with little intervening tissue disruption will result. If the bullet yaws while traveling through tissue, the permanent cavity will be enlarged and disruption of those inelastic tissues susceptible to the stretch of temporary cavitation will be greatly enhanced. A small punctate entrance wound will be present and the exit wound may be punctate, oblong, or stellate depending on the bullet yaw angle on exit. M855 can produce insignificant wounds, similar to those produced by .22 long rifle if the bullets do not fragment or yaw. This can be caused by velocities below approximately 2500 f/s as when fired from short barrel weapons, when the range increases beyond 150 yards, or if the bullets pass through only minimal tissue, such as a limb or the chest of a thin, malnourished individual--when this occurs, the bullet exits the body before it has a chance to yaw and fragment at the cannelure. Performance of the older 55 gr M193 FMJ is nearly identical to the M855 discussed above.

In testing, the 55 gr M193 style FMJ exhibits minimal fragmentation and deformation after first passing through an interior wall. Strangely, the Winchester 62 gr M855 FMJ (RA556M855) “green tip” had exactly the opposite performance when first hitting an interior wall; it exhibits significant early fragmentation, with only the steel core tip penetrating beyond 19 cm. The lack of fragmentation by the 55 gr M193 FMJ when penetrating interior walls make it a poor choice when decreased penetration is desired during entry or urban operations. Both M193 and M855 offer poor performance after penetrating automobile windows, as they tend to disintegrate into small fragments which give insufficient penetration.

Acceptable performing 5.56 mm/.223 ammunition choices for law enforcement duty in 1 in 9" or faster twist barrels are noted below:

Black Hills 60 gr JSP
Winchester M-855 62 gr FMJ (RA556M855)
Federal 62 gr Tac JSP (LE223T3)
Winchester 64 gr JSP (Q3246)
Black Hills 68 gr JHP
Federal 69 gr JHP (223GM)
Winchester 69 gr JHP (S223M)
Black Hills 73 gr JHP
Black Hills 75 gr JHP
Hornady 75 gr TAP (80265)

The ONLY .223 load we shot which offered adequate penetration after shooting through automobile windshields was the Federal 62 gr Tactical (LE223T3). The trade off is that the Federal Tactical does not fragment, maintains the deepest penetration of any .223 bullet after penetrating walls, and as a result, may not be the best choice for entry or urban settings. (The older Federal 55 gr Tactical (LE223T1) for 1/12 twist weapons offers the same type of deep penetration and performance against automobile windows) The other .223 loads listed above which offer good performance for entry or other anti-personnel applications had insufficient penetration and retained mass after shooting through the car windows.

Unlike their .308 bretheren, the polymer tip .223 loads such as the Hornady 60 gr TAP (83286) and Winchester 50 gr Ballistic Silvertip (SBST223) have inadequate penetration in soft tissue and truly dismal performance when faced with penetrating glass.

The Federal 62 gr JSP Tactical (LE223T3) and Hornady 75 gr TAP are the only .223 bullets which we have tested which exhibit adequate terminal performance when fired out of barrel lengths shorter than 14.5 inches, however, effective engagement distance is limited compared to longer barrels.

5.56 mm/.223 weapons with a 1 in 12" twist rate are generally limited to bullet weights of 55 grains or less. At this time, only two ammunition choices are available which offer adequate penetration: M-193 55 gr FMJ and Federal 55 gr Tactical JSP (LE223T1), neither of which is ideal for CQB or entry use, as they fail to fragment when after penetrating interior walls.

posted 11-23-2001 12:13            

--Fackler ML, Surinchak MA, Malinowski JA, Bowen RE: "Wounding Potential of the Russian AK-74 Assault Rifle". The Journal of Trauma. 24(3):263-266; 1984.

--Fackler ML and Malinowski JA: "Internal Deformation of the AK-74; A Possible Cause for its Erratic Path in Tissue". The Journal of Trauma. 28(No.1 Suppl):S72-S75; January 1988.

Wound profiles of the 5.45 x 39 mm can be found in several papers, including:

--Bowen TE and Bellamy RF (ed). "Chapter II: Missile Caused Wounds", Emergency War Surgery: Second United States Revision of the Emergency War Surgery NATO Handbook. Washington D.C., U.S. Government Printing Office, 1988.

--Fackler ML: “Wound Ballistics: A Review of Common Misconceptions”, Journal of the American Medical Association. 259(18):2730-2736; May 1988.

--Fackler ML: "Wounding Patterns of Military Rifle Bullets". International Defense Review. 1:59-64; 1989.

posted 11-23-2001 17:45               

How far does the SS109 typically penetrate in ballistic gelatin when it strikes at a velocity greater than 2700 fps?

posted 11-24-2001 04:10            

It is difficult to generalize SS109 terminal performance--it would be more accurate to discuss M855, C77, L2A2, or specify the manufacturer or country of origin of the SS109 bullet in question.

posted 11-27-2001 18:34            

If you go to the TM 43-0001-27 (Ammo) it specifies that the measurement is 3025 fps 78 ft from muzzle.

posted 11-27-2001 20:43            

We did not test the Federal 62 gr JSP Tactical or Hornady 75 gr JHP TAP out of the 8.5” barrel HK53, only the 10.5” barrel Colt Commando, so I can not answer your question with complete accuracy. The Federal Tactical will likely not fragment if fired through interior walls with an HK53 and will probably penetrate more deeply than the Hornady TAP, but I can not verify this with specific tests using the HK53. I suspect that the TAP will be your best choice for entry, but I cannot prove it for your specific weapon.

What do you mean by “overpenetrate”? In most cases, underpenetration is a more significant problem than overpenetration. With shots to the center of mass, if the bullet fails to have enough penetration to reach the large blood bearing vessels and organs in the torso, rapid physiological incapacitation is unlikely and your opponent may remain a lethal threat to you or the person(s) you are defending. Conversely, if your bullet completely penetrates the criminal who is attacking you and exits downrange, your bullet will certainly have had enough penetration to reach the large blood bearing vessels or organs in the torso. As a result, it is more likely to have caused sufficient hemorrhage to induce hypovolemic shock--the only reliable method of physiological incapacitation in the absence of CNS trauma. I suspect that law enforcement officers should worry more about the 85% or more of shots fired which completely MISS the intended target and immediately result in a significant threat to any person down range, rather than excessively worry about the relatively rare instance where one of the 15% of shots fired which actually hits the intended target, then exits in a fashion which still poses a hazard.

I am sorry that you must use the HK-53, as it has significant limitations. The short 8.5" barrel length of the HK-53 reduces the muzzle velocity of .223 bullets to the point where most loads do not fragment when fired out of this weapon. All you get is .22 LR performance. Would you stake your life on a .22LR ? In most cases, your duty handgun will cause more damage than an HK-53. Even with the best ammunition, you have a carbine which is marginally effective to at most 50 yards. In addition, the HK53 muzzle blast is severe—I imagine shooting an HK53 indoors on an entry is very uncomfortable—I hope you use hearing protection! Why not use the HK33? The overall length is not that different, yet the terminal performance with the 15.3” barrel is drastically improved--you have a carbine that is useful to 100-150 yards. Pat Rogers had an excellent article in the December 2001 SWAT magazine addressing LOP and stance--one point he makes is to shorten the M4 stock--close it all the way or only open it to the first position. This works very well and is what I do when carrying an M4. You could use the HK33 collapsible stock and shorten it down with your body armor and have the benefits of a compact weapon, but much better terminal wounding capability.

STLRN:

posted 11-27-2001 21:10            

That is the spec for the ammo, not a test result for a specific lot. An old manual I have states for lot acceptance testing of military ammo, the standard is +/-3 MPS (I know I doubt that standard is really kept). When the military does a lot of its down range testing they don't fire full power rounds, but ballistically similar reduced loads in order to eliminate some of the variables of exterior ballistics that might skew testing.

posted 11-28-2001 16:28            

I do not know how engineers or others calculate “MV”, but in all of our wound ballistic research the muzzle velocity of each shot is calculated using an Oehler Model 35 chronograph and three Skyscreen II photoelectric screens placed at 2 foot intervals beginning 3 feet from the muzzle.

For reported impact velocities, three chronograph screens are placed at 2 foot intervals with the last one positioned within 1 foot of the target.

When I performed research with Dr. Fackler at the Wound Ballistic Research Lab in the Letterman Army Institute of Research in the 1989-1991 time frame, velocities were measured in a similar fashion.

Most of our testing is done indoors to eliminate external ballistic interferences. Lake City, Crane, and some of the other government facilities have long range testing sites which are protected from external ballistic environmental interferences, so this should not be an issue.

posted 11-28-2001 23:30            

Rotational velocity of a projectile is dependant on two things: Rate of twist and linear velocity.

Rotational velocity degrades much slower than linear velocity.

posted 11-29-2001 01:28            

For the record, Buford Boone is a very experienced wound ballistic researcher; although we work on opposite sides of the country, our test results are generally very similar. This is possible because both of our research efforts employ scientific, repeatable, test methodology. The hallmark of good science is that an experiment is reproducible by others. The leading wound ballistic researchers share information and publish not only the testing results, but also the test methodology, so that other investigators can replicate their experiments. This serves as a check to either confirm each other's results as being valid or discover possible points of error. There are no secrets….when secret “data bases”, secret “experiments”, and secret “street results” are invoked to hinder critical analysis and review of an author’s claim, invariably deceit, fabrication, and falsehood are lurking.

posted 12-11-2001 19:20            

quote:

---

Originally posted by Buford Boone:
Rotational velocity of a projectile is dependant on two things: Rate of twist and linear velocity.

---

I noticed this at OlyArms when the 6" bbled ARs wouldn't stabilize 55 gr ball. The twist had to be bumped up to keep the projos point first.

In that vein, does rotational velocity contribute to wounding?

DocGKR may remember that I once made him an offer of 4 16" barrelled AR uppers, headspaced alike, in twists 7" through 14" to test this. But I fell off the face of the earth and just recently got back.

posted 12-12-2001 23:01            

Yes, and no. Rotational velocity can effect wounding by allowing, or not allowing, proper expansion of the projectile.

Theoretically, if the rotational velocity is high enough, the projectile could remain stable in tissue. In reality, this level of rotation would probably spin most expanding projectiles apart. I have video of this happening with a lightly constructed .223 fired from a fast (1:7) barrel.

posted 12-17-2001 03:54            

quote:

---

Originally posted by DocGKR:
[snip]the most significant effect of rotational velocity on wounding is the role it plays in bullet stabilization or lack thereof.

---

From that can I deduce that the amount of stabilization in the .223 cartridge varies little between the different length/twist/velocity combinations (obvious mismatches, such as subsonic 80 gr. in a 1X14" aside) and as such isn't a significant factor in wounding?

Or, are there certain length/twist/velocity combinations that create more significant wounds?

I'm grokking this secure in the knowledge that many .223 projectiles will fragment above 2700 fps. I'm wondering about what happens when that velocity isn't met; how to maintain the same degree of damage with a lower velocity and what would have to be a different bullet.

The question I am trying to answer is, "What bullet will fragment reliably at velocities in the 2100 to 2700fps range?"

I'm also wondering if the longer bullets you mentioned show larger wounds because there is simply more bullet to start with?

As for;
"The Federal 62 gr JSP Tactical (LE223T3) and Hornady 75 gr TAP are the only .223 bullets which we have tested which exhibit adequate terminal performance when fired out of barrel lengths shorter than 14.5 inches"

In that section I'm seeing lower velocity (short barrel) longer bullet. Perhaps the rotational velocity of these loads was slower than optimum and that was why only they 'exhibit adequate terminal performance'? Or is it simply the bullet construction in these loadings?

And in the arena of 'subsonic 80 gr. in a 1X14"' have any studies been done on the recent subsonic .223 loads? I'm imagining a No. 2 pencil stabbing.

For BB,
re. It's odd you mention that occurence, I've been told time and time again that that "just can't be" and "is mathematically impossible" while relating stories of a similiar event. Looks like I need a REALLY good digital cam huh?

As for 'test it under expected conditions' I assume you mean take that load and fire it out of the intended rifle at the range expected at the targets desired. Not actually take it out and test it.

Thank you to both of you for the time in answering these questions, and thanks for being on the BBS.

I apologize for all the questions in advance but this is the only hobby that I have left. I ruined the others by turning them into work.