Q: How does 5.56 compare against other Military rounds in terms of weight?

A: See the article Ammo by Weight

Q: Was the 5.56 "Designed to Wound not Kill"?

A: No!!  For a complete explaination see LTC Santose's Article.

Q: Does Twist Rate effect the wounding capability of 5.56 (i.e. is 1:14 MORE effective)?

A: No.  For a full details from the foremost researcher in the field, check out the link for the next Q&A and Chuck's reply a little further down.

Q: How does the 5.56's wounds compare to other Military rounds (7.62NATO, 7.62x39, 5.45x39..)?

A: Under nomal combat conditions (engagements at 100 yards or less), on torso hits, it can make a much larger wound channel.  Check out this link for the hows & why (with pictures).

Military Rifle Wound Bullet Patterns By Dr. Martin Fackler

Patterns of Military Rifle Bullets By Dr. Martin Fackler (an article similar to the first in content, but covers some of the 'why we study it this way' and raises other questions).

Q: Isn't the newer 5.56 62gr green tip (M855) round less effective than the older 55gr FMJ (M193)?

A: Somtimes  For a comparison of the wounding capabilies of M193 vs M855 see the link provied in the previous Q&A (see their wound profiles by looking [HERE] ).  Recently there has been research into this issue, especially relating to short barrel weapons (14.5" and less).  Short barrels greatly reduce the 'fragmentation' range of the round so you'll get poor performance at ranges beyond 100 yards (or closer).  Also there was a recent paper (Luke Haag in the AFTE Journal (33(1):11-28, Winter 2001) ) describing different performance between different lots of ammo.  Some M855 was not yawing until 7" of penetration (which would be bad if you're facing thin/undernourished opponents).  It seems there are bullet construction issues with M855 that can cause it to have different terminal performance from lot to lot.  This is one reason why many Special Operations Units are now using Mk 262 Mod 0 or Mk 262 Mod 1 in their M4s.  [Editor: Many thanks go to Dr. Roberts for letting us know about the manufacting issue and Mr. Haag's paper]

Q: What is the Mk 262 Mod 0 and Mk 262 Mod 1 Ammo?

A: Information gathered from the writings of Dr G.K. Roberts and Pat Rogers.

Mk262 is a 77gr Open Tip Match (OTM) round that was initially used with the MK 12 SPR (18" sniper variant M4).  The Mod 0 used the Sierra Match King (SMK) 77gr round, loaded by Black Hills.  This was round worked well with both the SPR and the M4s, but as it had no cannalure there were problem with bullet set-back.  This was solved with the Mod 1 loading.  The Mod 1 loading uses a new 77gr SMKwhich has a cannalure (originally the Nosler 77gr OTM was looked at - the Nosler has a cannalure and starts fragmenting earlier, however it is not as accurate as the SMK).  The resulting round was more reliable (as there was no bullet set back issue).  This round is also produced by Black Hills.  One nice thing about the Mk 262 loads is they are very low flash.  Flash retardants are used in their powder (unlike many M193 & M855 loads) so they can be used effectively at night even with bare muzzles.

 Q: Didn't Black Hawk Down demonstrate the poor performance of the M855 5.56 round?

A: No, in the book only one person complained about M855 (and he did so twice).  Please check out the two articles by Chad (the second is linked to the first) concerning the noted effects of M855 in Black Hawk Down and other books on battle experiences.

Q: Isn't using of 5.56 inside of buildings (for defense) more dangerous than pistol rounds.

A: Courtesy of Julius Chang

In a word 'NO' its the opposite. See the references here (both published and online links).

Q: Does the 5.56/.223 really tumble on impact? Does a faster/slower twist rate help?

A: Courtesy of LTC Chuck Santose

In the 1960s we all thought bullet tumbling on impact was a unique and wonderful effect of 1:14 rifling and there was much controversy when the Army adopted the "inferior" 1:12 rifling.

Since that time Army medical research in 1988, confirmed by later ballistic research, has confirmed that (1) all bullets longer then their diameter will tumble in animal tissue, (2) tumbling bullets cause only small additional wounds, much like hollow points, and (3) the massive wounds caused by M193 and M855 Ball are caused by bullet fragmentation tearing the walls of the temporary cavity resulting in 150mm wounds. Temporary cavity requires rifle velocity target strikes (pistol bullets have very minor temporary cavities if at all) and the fragmentation of these rounds does not occur below 2500fps, or about 150 meters.

Russian 7.62x39 and 5.45mm bullet tumble on impact, but have wounds that are much, much smaller than 5.56mm wounds.

In short there is no measurable difference between M193 Ball 5.56mm wounds fired from 1:14, 1:12, or 1:7 rifling twists and M855 Ball is almost identical from 1:7 and 1:9. M855 is too unstable to consider shooting from 1:12 barrels. Bullets which strike sideways probably won't get enough penetration to do any real damage.

Go to http://www.firearmstactical.com and read their "briefs" for more information (as well as the references in the previous question).  A good starting point is their page on Wound Ballistics.

Q: I want to choose a defensive ammo besides FMJ what should I use?

A: Data provided by Chuck Santose

How 'bout these. Remember that 12" penetration is MINIMUM. Over 18" is wasted. Listed by bullet weight:

These are in bare 10% ballistic gelatin and represent the average one can expect in animal tissue.

Cartridge	Penetration(inches)
Fed Frang 26gr	7.8
Simunitions Frang 36gr	6.1
Fed 40gr JHP	6.7
Glaser Safety Slug 45gr	7.7
Win 50gr JSP	12.4 *
Win 53gr JHP	8.0
Fed 55gr JHP	9.6
Fed 55gr JSP Tactical	16.8 *
Rem 55gr JSP	10.6
Win 55gr FMJ M193	14.3 *
Win 55gr JSP	9.3
Black Hills 60gr JSP	11.5
Rem 60gr JHP Match	11.5
Win 62gr FMJ M855	14.7 *
Win 64gr JSP cannelure	9.5
Win 64gr JSP smooth	14.9 *
Win 64gr SWP knurled	13.8 *
Black Hills 68grJHP	12.1 *
Fed 69gr JHP-BT Match	14.7 *
Win 69gr JHP-BT Match	11.9
Fed 70gr JHP VLD	10.0
Black Hills 75gr JHP Match	13.3 *
Black Hills 75gr JHP Moly Match	12.2 *

From Table 1, "The Wounding Effects of 5.56mm/.223 Law Enforcement General Purpose Shoulder Fired Carbines....", IWBA Journal, Vol 3, No. 4 (1998)/

* Over 12"

How many of these do you see you can buy, and what do they offer that M193 and M855 don't?

Q: What .223 round should I use when hunting Whitetail Deer?

A: Courtesy of Michael Sierchio

Federal GM223M - 223 Rem (5.56x45), 69 Gr, B-T HP Match at about $15 a box.  Or you can use the Winchester 64gr Power Point (recommended by many on AR15-L) NOT the new Power Point PLUS.

Q: What is a recommended round for LEO Duty use?

A: (Reprinted from posts by Dr. Gary K. Roberts [docGKR] at The Tactical Forums)

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 brethren, 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.

. . . . . . . . .

In .223, the 75 gr TAP is one of the best performing bullets in this caliber, as demonstrated in the lab, as well as confirmed by multiple law enforcement and military shooting incidents. The .223 40 gr and 60 gr TAP bullets seem to offer inadequate penetration. [This round will work out of a 1:9 twist barrel, but is probably better out of a 1:7 twist.]

. . . . . . . . .

For .223, your mission and specifics of your weapon (barrel twist and length) are significant factors in what ammunition to choose. If you need to engage a vehicle, the only widely available commercial .223 loads with acceptable performance are the Federal 62 gr Tactical JSP (LE223T3) or Federal 55 gr Tactical JSP (LE223T1), both of which use the Trophy Bonded Bearclaw Bullet.

Editor's Note: Dr. Roberts has noted: "The Federal Premium Rifle P223T2 uses the same 55 gr JSP Trophy Bonded Bear Claw Bullet as the Federal Tactical 55 gr JSP LE223T1.".  The Premium Rifle load is much more available than the Federal Tactical load.

For anti-personnel use if you have a 1/7 twist barrel, the Hornady 75 gr TAP, Sierra 77 ...*, Nosler 77 gr BTHP, and new magazine length 100 gr BTHP loaded by Black Hills are the best choices. The PRL 87 gr bullet is another possible choice which appears to offer excellent incapacitation potential, however this bullet’s design does not appear to have been perfected at this time—it’s terminal performance is somewhat inconsistent, it is not available in large quantities, and it is relatively expensive.

*Editor's Note:  Dr. Roberts has indicated he no longer considers the 88gr SMK a great choice because it penetrates too deep before yawing - hence this recomendation has been removed from his orginal post

FWIW, in our preliminary testing, the 100 gr BTHP loaded by Black Hills exhibited the best terminal performance at CQB distances we have ever seen with a .223 bullet.

[Maintenance FAQ]