reply to post by Grozny07
5.56mm is a good round when it is matched with the right barrel. The round can do massive damage if it is used with the proper rate of twist
and barrel length.
Absolutely correct, but you did not mention round fragmentation range which heavily depends on the barrel length and its twist. We all know that
originally 5.56 was designed as a high velocity varmint round, and was modified into a military round.
Its fragmentation effect was created by thinning the copper jacket wall, a lesson learned from the experimentations going back to the early 20th
century by Russians and Japanese.
After encounters with the Chinese, it became obvious that Japanese Type 38 6.5X50SR was to mild, and one of the round modifications included a
shortened thin walled 6.5 bullet, which was rejected do to its greatly reduced penetration capabilities and increased instability, which essentially
is the exact same problems with 5.56.
Japanese went with a traditional 7.7X58 in the end.
Another fascinating historical development which is completely unknown in the West is what was the true mass produced assault rifle in the world,
which preceded German MP-43/Mp-44 Stg.44 with its intermediate cartridge by more then 3 decades.
The rifle was a fully automatic, 600 rof Fedorov "Avtomat" assault rifle with a 25 round magazine, it was to be chambered for a dedicated rimless,
reduced recoil round designed by Fedorov himself, but do to abundance of Japanese 6.5X50SR it forced the adoption of the Japanese round instead of
costly development and manufacturing of Federovs rimless.
The rifle development began in 1906, final version came about in 1911, it was incredibly effective, and unlike BAR of 1918 it weighs only 9 ½ pounds
thus falling into the modern assault rifle category rather then intermediate MGs like BAR, Lewis, etc.
Even with Japanese 6.5mm Fedorov experimented with fragmenting qualities of light thin walled bullets, and proposed a mixed load of equally weighted
fragmenting and penetrating rounds, thus creating the concept of mixed ammunition feeds.
Even after such clear history of light, small diameter rounds, 5.56 suffers from the same flaws which were known over 50 years before.
M4s various barrels, with lengths of 14.5” to 16” and various twists of 1/7, 1/9, 1/10, all suffer from the same fundamental problem. In order to
compensate for the lower muzzle velocity and to increase range, do to rapid loss of energy round fragmentation can no longer be achieved at ranges
over 100 yards.
Over 100 yards M4 rounds just make small holes with out the devastating fragmentation effect, thus basically turning M4 into a full auto .22, and just
as in Vietnam, it’s the major complaint of US soldiers which use the short barreled M16s.
Some argue that M4s are designed to be used in close quarter combat which takes place under 100 meters, and the 5.56 is sufficiently effective,
another fundamental problem is the very same fragmentation/ricochet properties of the round.
Combat in under 100 yards is considered urban warfare, which involves fighting in and around buildings and over paved roads. In such conditions ALL
small caliber rounds suffer from the same problem, fragmentation/ricochet.
Both 5.56 and 5.45 are completely unsuited for clearing buildings because they fragment/ricochet all over the place, and pose as much danger to the
shooters as to their intended targets.
Good old 7.62mm (both 25 and 39) and 9mm are used to this day to specifically clear buildings, simply because they are more effective then small
Modern body armor is not an issue with modern 7.62 and even 9mm pistol AP rounds, because all of them defeat all levels of even ceramic composite
plates at ranges up to 25 yards.
Using heavier rounds in conjunction with the right length barrel (with a twist of 1:9, as favored by heavier rounds, and a length of 20" )
makes the round adequate.
Adequate but only with in certain parematers. Originally the fragmentation effect of the round was much more pronounced in the early 20” barrels
which had 1/14 and 1/16 twist, but the instability required to tumble the round was so great, that the round would deviate from its flight path even
when striking a leaf or blade of grass, and in the jungles of Vietnam that meant only LOS fire while almost all of small arms fire was indirect.
A good real life example of that is the encounter between small a NVA recon group and a marine patrol armed with early M1s and M60s, while NVA was
armed with SKS/AK-47s and a single RPD.
No forward assist, 20 round mags with weak springs that could take only 16 rounds with out causing certain feed stoppage.
Both forces were moving parallel to each other and were separated by a thick growth of bamboo.
When both forces became aware of each other, startled and uncertain of each other strength they engaged by sporadic fire through the bamboo. Bamboo
was tall and thick so grenades were out of the question, and everything counted of sheer firepower.
M16 rounds fragmented immediately upon impacting the bamboo, and all of M16 fire could do is cut a few feet into the bamboo, while only M60s could
send lead to the enemy.
At the same time NVAs SKS/AK-47 and a single RPD sent their 7.62X39 rounds straight through the bamboo and effectively pinned down a force
outnumbering them 4 to 1.
When M60s began to jam, Marines had no choice but to gather their casualties and pull out, while calling in artillery and air strikes to cover their
retreat. In aftermath not a single NVA casualty was confirmed, because even before Marines began to organize their retreat, small NVA group simply
began running out of ammo and were pulling out them selves.
Do to effective volume of firepower Marines were receiving, they greatly overestimated numbers of the NVA they encountered, which in turn resulted in
needless reinforcements of their positions, and pulled vital resources from areas that desperately needed them at the time.
Unnecessary recon flights, blind artillery fire, bombing missions that only bombed the jungle, all because M16 rounds could not go through some
Small rounds do not always mean less damage; the Afghans didn't call the Russian AK-74's 5.45mm round the "poison bullet" for nothing. The
shock of a round entering the body at such high speeds is ugly.
While essentially true it’s not entirely correct.
5.56 relies on inherent instability, high velocity and thin jacket wall to tumble and fragment into small pieces, while 5.45 relies on a specifically
designed feature which is not as dependent on round velocity.
5.45 bullet has a hollow cone, or as Russians call it “phased center of gravity”
, which upon impact immediately deforms thus causing severe flight path deviation, tumbling and full energy transfer into its target, which allows it
to keep its deadly properties at longer ranges and lower velocities.
At the end of its trajectory, 5.45s cone deforms and simply smack through the target with a similar effect of a hollow point round, but on the
While hollow points expansion is dependant on its velocity at the time of impact and the density of the material it is hitting, 5.45 deforms but does
not have the energy to tumble, thus simply pushing through until it transfers all of its remaining energy.
Currently the deadliest fragmenting round is the German 7.62X51, which is lighter, faster and has a fragmenting grove in the middle of the bullets
body, which tears the bullet in two parts when it enters the target, thus effectively turning a single bullet into a bullet that has the effect of two
bullets when it strikes its target.