3:41 am by digitalmbul in Riffles
Improvements over the M16A1 –
a heavier, stiffer barrel than the barrel of the M16A1
a redesigned handguard, using two identical halves, with a round contour which is sturdier and provides a better grip when holding the rifle
new buttstock and pistol grip made of a tougher injection moldable plastic that provides much greater resistance to breakage
an improved rear sight which can be easily adjusted for windage and range
a modified upper receiver design to deflect ejected cartridges, and preclude the possibility of the ejected cartridges hitting the face of a left-handed firer
a burst control device, that limits the number of rounds fired in the automatic mode to three per trigger pull, which increases accuracy while reducing ammunition expenditure
a muzzle compensator, designed to reduce position disclosure and improve controllability and accuracy in both burst and rapid semi-automatic fire
a heavier barrel with a 1 in 7 twist to fire NATO standard SS 109 type (M855) ammunition which is also fired from the M249 Squad Automatic Weapon (SAW). This further increases the effective range and penetration of the rifle cartridge. The M16A2 will also shoot the older M193 ammunition designed for a 1 in 12 twist.
1:58 am by digitalmbul in Riffles
Modern sniper rifles
last updated: 26 jan 2001
The main purpose of the sniper rifle is to destroy valuable targets at
extended ranges with aimed fire, and with as few ammunition
as possible. In most cases, “the target” means the human being (enemy
soldier, armed criminal, terrorist, president etc.), and
the “as few ammunition as possible” often means “one shot”. The range for
sniper fire may vary from 100 meters or even less
in police/counter-terror scenarios, or up to 1 kilometer or more – in
military or special operations scenarios.
Some sniper rifles, mostly – large caliber ones, used also as anti-material
weapons, to destroy, or, more often, render
unusable or unoperable, targets such as radar cabins, jeeps, parked
History of sharp-shooting traces its ancestry well back into XIX or even
into XVIII centuries. Early sniper rifles were standart
issue army rifles, selected for accuracy, or privately purchased
commercial target or hunting rifles. During WW I and WW II
both sides used a lot of general issue bolt action rifles (such a
Russian/Soviet Mosin M1991/30, US M1903A4, British SMLE
No.4(t), German G98k etc.) fitted with some kind of telescopic sight. Some
of general issued semi-auto rifles also were used
in sniper role, such as Soviet SVT-40 and US M1 Garand.
bolt action rifle topped with powerful scope for long-range shots The
practice of developing the military sniper rifles from
standart issue firearms is still used in many countries. Ususally,
manufacturer or special military unit select some rifles for
their better-than-average accuracy, then adopt these rifles for sniper role
(i.e. convert them from select-fire into semi-autos,
add ajustable stocks, bipods, scope mounts etc.). Many of military sniper
rifles, discontinued in service or currently in use,
such as US M21, German G3-ZF and G3-SG/1, were made that way.
Some sniper weapons were made for marksmen use from the scratch, because
the clients wanted some special
characteristics, that were unavailable in any service or commercial
weapons. One such example – Soviet SVD Dragunov
rifle. It was designed on Soviet Army request as a lightweight, powerful
and reliable semi-auto rifle, and remains in service
for almost 40 years.
But wast majority of sniper rifles, especially – police ones, were designed
on existing commercially available hunting
or sporting rifles. The best examples – the US military sniper rifles M24
and M40, along with many custom police rifles,
were (and still are) built on Remington 700 actions, available for general
public in many hunting and target rifles. Famous
SIG-Sauer sniper ifles also buil on their (SIG or Sauer) hunting rifles.
Some sniper rifles, mostly also police ones, designed
on target/sporting rifles. To name few: Blaser R93 Tactical (Germany),
Sv-98 and MC-116 (Russia).
In general, all sniper rifles may be rougly separated into 3 major
categories: Miltary sniper rifles, Police/Law Enforcement
tactical/sniper rifles, and Special purpose sniper rifles.
Military sniper with it’s gear and camo suit Military sniper rifles used by
different military units. Along with main requirements
for accuracy and sufficient effective range, military use commands some
other: military sniper rifle must not be too heavy,
because sniper usually must carry it for the long hours, with ammunition
and other stuff. Also, military sniper rifle must be
extremely reliable in any weather and climatic conditions and could
withstand hundreds of rounds fired without cleaning
and maintenance and without any loss of accuracy. Third, military sniper
rifle must be easy to fieldstrip and easy to repair
in field conditions. Also, military sniper rifle often must have backup
iron sights, in case of telescope breackage.
Another requrement is that military sniper rifle must use military
ammunition, conforming to international war threaties and
generally available to the troops. In most cases, military sniper rifle use
variants of the standart caliber army cartridges
(such as 7.62mm NATO or 7.62x54mm R), specially developed for sniping.
Effective range for the standart-caliber sniper rifles against the single
human-sized target may be estimated as 700-800
meters for first-shot kills. To extend effective range beyond 1000 meters,
often used sniper rifles, designed to fire more
powerful ammunition, such as .300 Winchester magnum (7.62x67mm) or .338
Lapua magnum (8.6x70mm).
Military sniper rifles may be further separated in two tactically diffrent
categories: the sniper rifles itself, designed to
achieve aimed hits at long distances, and the Designated Marksman Rifles
(DMR), designed to provide accurate fire
support for line troops. While the “true” sniper rifles usually are bolt
action ones, to achieve maximum accuracy, the
DMRs usually are semi-autos, such as Russian SVD or German G3ZF or MSG-90,
to gain higher rate of fire. But the
difference lays more in tactical applianses, than in the rifles itself.
Police / Law Enforcement (LE) sniper rifles are somewhat another kind of
tools. If in most military/war scenarios wounded
enemy is equivalent to killed enemy, or even better, in LE and
counter-terror (CT) scenarios wounded criminal or terrorist
may lead to many innocent wictims. Sometimes, the LE or CT sniper must not
only kill the terrorist, but hit the particular part
of the body – head, or hand, holding the gun, etc. So, in general, LE and
CT sniper rifles require more accuracy, but at
shorter distances. The majority of LE or CT scenarios require precision
shooting at the distances lesser that 300, or even
100 meters. These scenarios also require really few shots per scenario -
sometimes one and the only one shot. This also
require extreme accuracy and stability of results in any weather
conditions. LE and CT snipers also has no limitations on
caliber and ammunition selection, so they could select almost any
caliber/cartridge they department want, or can afford.
Usually, LE/CT sniper rifles had completely ajustable stocks to suit
snipers of different statute, sometimes they got
half-of-dozen ajustable screws. This is absolutely unsuitable for military
sniper rifles, but for LE sniper rifles, which are
usually carried to the point of action in special cases, this is OK.
Many USA made LE sniper rifles are built on the hunting “varmint” rifles.
Varmint rifles are small or medium caliber
hunting rifles, designed to kill small pests, such as squirrels, rabbits
etc., at extended distances. Some LE sniper rifles,
such as Remington 700 Police, are simply Remington 700VS varmint hunting
rifle barreled actions, bedded into
In Europe, some sniper rifles built on sniper rifles (such as Mauser 66,
SIG-Sauer SSG2000, Blaser R93 Tactical), and
some built on hunting rifles (such as Steyr Scout Tactical). LE/CT sniper
rifles use many kinds of ammunition, from .22LR
for training and short-range sniping, to .308 Win, 6.5x55mm, .300 Win
Special Purpose sniper rifles may be, in turn, splitted into 2
Large-caliber rifles for ulra-long range sniping and ani-material use, and
silenced rifles for covert operations.
Large caiber sniper rifles usually built to use heavy machineguns
ammunition, such as .50BMG (12.7x99mm) or 12.7x108mm.
Effective range of such rifles is up to 1500 meters and above, depending on
size of target and quality of the ammunition.
General purpose machinegun ammo usually produced not-too-good accuracy, but
recently some special “sniper”
rounds developed in .50BMG caliber.
Silenced sniper rifles usually are used with special sub-sonic ammunition
and removable or integral silencers to produce
lower sound report. Sub-sonic ammo decreases effective range down to
300-400 meters, but it’s worth. With the correct
ammo and silencer, the sound of the gunshot could be easily mised
completely at the distances of 100-200 meters at night,
or even at 30-50 meters – in daily urban noize.
Sniper rifle Accuracy
The most common way of describing the accuracy of the sniper rifle is to
measure average diameter of the circle, that
may be drawn arount the group of bullet holes in the target. Usually, the
rifle is fired from the rest with groups of the 5 (or 3)
rounds, and then every group is measured. Average group diameter is the
most common criteria of rifle accuracy.
Today, the thin line between “good” and “poor” accuracy is usually laid in
1MOA group. 1 MOA (Minute Of Angle) is
measure of the angle, that formed with the triangle with muzzle as the top
and the group as the base. 1 MOA is roughly
equivalent to 1 inch group diameter at 100 yards (91 meter), or to 2 inches
at 200 yards etc. So, if you read that rifle XXXX
shooths 1MOA groups, it means that at 300 yards this rifle could place 5 or
so bullets in circle of no more than 3 inches in
diameter. Many modern sniper rifles, when loaded with right ammunition,
could shoot 0.5MOA, or even 0.3MOA, which
mean 1 inch groups at 300 yards, or 2 inch (50 millimeters!) groups at 600
yards (550 meters).
(c) Max Popenker, 2001
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