.223 Remington

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.223 Remington
223 Remington.jpg
A variety of .223 Remington cartridges with a .308 Winchester (right) for comparison
Place of originUnited States
Production history
Designer Remington Arms
Variants.223 Ackley Improved, 5.56×45mm NATO
Parent case .222 Remington
Case typeRimless, bottleneck
Bullet diameter0.224 in (5.7 mm)
Neck diameter0.253 in (6.4 mm)
Shoulder diameter0.354 in (9.0 mm)
Base diameter0.376 in (9.6 mm)
Rim diameter0.378 in (9.6 mm)
Rim thickness0.045 in (1.1 mm)
Case length1.76 in (45 mm)
Overall length2.26 in (57 mm)
Case capacity28.8 grain H2O (1.87 ml)
Rifling twist1 in 12 inch (military-style rifles use 1:7 to 1:10 to stabilize longer bullets)
Primer typeSmall rifle
Maximum pressure (SAAMI)55,000 psi (380 MPa)
Maximum pressure (CIP)62,366 psi (430.00 MPa)
Maximum CUP52000 CUP
Ballistic performance
Bullet mass/typeVelocityEnergy
36 gr (2 g) JHP 3,750 ft/s (1,140 m/s)959 ft⋅lbf (1,300 J)
55 gr (4 g) Nosler ballistic tip3,240 ft/s (990 m/s)1,265 ft⋅lbf (1,715 J)
60 gr (4 g) Nosler partition3,160 ft/s (960 m/s)1,325 ft⋅lbf (1,796 J)
69 gr (4 g) BTHP 2,950 ft/s (900 m/s)1,338 ft⋅lbf (1,814 J)
77 gr (5 g) BTHP 2,750 ft/s (840 m/s)1,301 ft⋅lbf (1,764 J)
Test barrel length: 24 inches (61 cm)
Source(s): [1] [2]

The .223 Remington (designated as the 223 Remington by the SAAMI [3] and 223 Rem by the CIP [4] ) is a rimless, bottlenecked rifle cartridge. It was developed in 1957 by Remington Arms and Fairchild Industries for the U.S. Continental Army Command of the United States Army as part of a project to create a small-caliber, high-velocity firearm. The .223 Remington is considered one of the most popular common use cartridges and is currently used by a wide range of semi-automatic and manual-action rifles as well as handguns.



From left: .222 Remington, .223 Remington, and 5.56x45mm NATO Cartridges .222 Remington, .223 Remington & 5.56x45mm NATO.jpg
From left: .222 Remington, .223 Remington, and 5.56×45mm NATO

The development of the cartridge, which eventually became the .223 Remington, was linked to the development of a new lightweight combat rifle. The cartridge and rifle were developed by Fairchild Industries, Remington Arms, and several engineers working toward a goal developed by U.S. Continental Army Command (CONARC). Development began in 1957. A project to create a small-caliber, high-velocity (SCHV) firearm was created. Eugene Stoner of ArmaLite was also invited to scale down the AR-10 (7.62×51mm NATO) design. [5] Winchester was also invited to participate. [6] [7]

CONARC ordered rifles to test. Stoner and Sierra Bullet's Frank Snow began work on the .222 Remington cartridge. Using a ballistic calculator, they determined that a 55-grain bullet would have to be fired at 3,300 ft/s to achieve the 500-yard performance necessary. [7]

Robert Hutton (technical editor of Guns and Ammo magazine) started the development of a powder load to reach the 3,300 ft/s goal. He used DuPont IMR4198, IMR3031, and an Olin powder to work up loads. Testing was done with a Remington 722 rifle with a 22" Apex barrel. During a public demonstration, the round successfully penetrated the US steel helmet as required, but testing also showed chamber pressures to be too high. [6] [7]

Stoner contacted both Winchester and Remington about increasing the case capacity. Remington created a larger cartridge called the .222 Special. This cartridge is loaded with DuPont IMR4475 powder. [7]

During parallel testing of the T44E4 (future M14) and the ArmaLite AR-15 in 1958, the T44E4 experienced 16 failures per 1,000 rounds fired compared to 6.1 for the ArmaLite AR-15. [7] Because of several different .222 caliber cartridges that were being developed for the SCHV project, the .222 Special was renamed .223 Remington. In May 1959, a report was produced stating that five- to seven-man squads armed with ArmaLite AR-15 rifles have a higher hit probability than 11-man squads armed with the M-14 rifle. At an Independence Day picnic, Air Force General Curtis Le May tested the ArmaLite AR-15 and was very impressed with it. He ordered a number of them to replace M2 carbines that were in use by the Air Force. In November of that year, testing at Aberdeen Proving Ground showed the ArmaLite AR-15 failure rate had declined to 2.5/1,000, resulting in the ArmaLite AR-15 being approved for more extensive trials. [7]

In 1961, marksmanship testing compared the AR-15 and M-14; 43% of ArmaLite AR-15 shooters achieved Expert, while only 22% of M-14 rifle shooters did. Le May ordered 80,000 rifles. [7] In July 1962, operational testing ended with a recommendation for the adoption of the ArmaLite AR-15 rifle chambered in .223 Remington. [7] In September 1963, the .223 Remington cartridge was officially accepted and named "Cartridge, 5.56 mm ball, M193". The following year, the ArmaLite AR-15 was adopted by the United States Army as the M16 rifle, and it would later become the standard U.S. military rifle. The specification included a Remington-designed bullet and the use of IMR4475 powder, which resulted in a muzzle velocity of 3,250 ft/s and a chamber pressure of 52,000 psi. [7]

In the spring of 1962, Remington submitted the specifications of the .223 Remington to the Sporting Arms and Ammunition Manufacturers' Institute (SAAMI). In December 1963, Remington introduced its first rifle chambered for .223 Remington a Model 760 rifle. [6]

Cartridge dimensions

The .223 Remington has a 28.8-grain H2O (1.87 ml) cartridge case capacity. [8]

.223 Remington.jpg

.223 Remington maximum CIP cartridge dimensions. All sizes in millimeters (mm). [4]

Americans would define the shoulder angle at alpha/2 = 23 degrees. The common rifling twist rate for this cartridge is 305 mm (1 in 12 in), 6 grooves, Ø lands = 5.56 millimetres (0.219 in), Ø grooves = 5.69 millimetres (0.224 in), land width = 1.88 millimetres (0.074 in) and the primer type is small rifle.

According to the official CIP rulings, the .223 Remington can handle up to 430.00 MPa (62,366 psi) Pmax piezo pressure. In CIP-regulated countries, every rifle cartridge combination has to be proofed at 125% of this maximum CIP pressure to certify for sale to consumers. [4] This means that .223 Remington chambered arms in CIP-regulated countries are currently (2016) proof tested at 537.50 MPa (77,958 psi) PE piezo pressure. This is equal to the NATO maximum service pressure guideline for the 5.56×45mm NATO cartridge.

The SAAMI pressure limit for the .223 Remington is set at 379.212 MPa (55,000 psi), piezo pressure. [9] [10] Remington submitted .223 Remington specifications to SAAMI in 1964. [7]

.223 Remington vs. 5.56×45mm NATO

In 1980, the .223 Remington was transformed into a new cartridge and designated 5.56×45mm NATO (SS109 or M855). [7]


The external dimensional specifications of .223 Remington and 5.56×45mm NATO brass cases are nearly identical. The cases tend to have similar case capacity when measured (case capacities have been observed to vary by as much as 2.6 grains (0.17 ml)), although the shoulder profile and neck length are not the same and 5.56×45mm NATO cartridge cases tend be slightly thicker to accommodate higher chamber pressures. When hand-loaded, care is taken to look for pressure signs as 5.56×45mm NATO cases may produce higher pressures with the same type of powder and bullet as compared to .223 Remington cases. Sierra provides separate loading sections for .223 Remington and 5.56×45mm NATO and also recommends different loads for bolt-action rifles as compared to semiautomatic rifles. [8] [11]


The Sturm, Ruger & Co. AR-556 has rifling at 1:8. Their Mini-14 rifles have rates of 1:9. Ruger's American bolt-action rifle is also in 1:8. [12] Smith and Wesson in their M&P15 also uses 1:9. [13]


Remington submitted the specifications for the .223 Remington cartridge in 1964 to SAAMI. The original pressure for the .223 Remington was 52,000 psi with DuPont IMR Powder. The current pressure of 55,000 psi (379 MPa) resulted from the change from IMR to Olin Ball powder. [7] The official name for .223 Remington in the US Army is cartridge 5.56 x 45mm ball, M193. If a 5.56×45mm NATO cartridge is loaded into a chamber intended to use .223 Remington, the bullet will be in contact with the rifling and the forcing cone is very tight. This generates a much higher pressure than .223 Remington chambers are designed for. [8] NATO chose a 178-mm (1-in-7) rifling twist rate for the 5.56×45mm NATO chambering. The SS109/M855 5.56×45mm NATO ball cartridge requires a 228 mm (1-in-9) twist rate, while adequately stabilizing the longer NATO L110/M856 5.56×45mm NATO tracer projectile requires an even faster 178 mm (1-in-7) twist rate. [7]


The .223 Remington and 5.56×45mm NATO barrel chamberings are not the same. [14] While the cartridges are identical other than powder load, bullet weight, and chamber pressure, a significant difference is in barrel of the rifle to be used, not in the cartridge. The 5.56×45mm NATO chambers are dimensionally larger in certain critical areas than .223 Remington chambers. As the chambers differ accordingly the head space gauges used for the two chamberings differ. [15]

By observation, 5.56×45mm NATO ammunition is not as accurate as .223 Remington in many of the AR type rifles extant, even with the same bullet weight. The .223 Wylde chamber specification developed by Bill Wylde solves this problem by using the external dimensions and lead angle as found in the military 5.56×45mm NATO cartridge and the 0.224 inch freebore diameter as found in the civilian SAAMI. 223 Remington cartridge. It was designed to increase the accuracy of 5.56×45mm NATO ammunition to that of .223 Remington. [16] Other companies also have chamber designs that increase 5.56×45mm NATO accuracy. [17]


The table contains some estimated pressures based on normal proofing practice and on the known increases in pressure caused by bullet setback (which is a similar occurrence with regard to pressure). The proof pressure of M197 is 70,000 psi. [18]

The following table shows the differences in nomenclature, rifling, throating, and normal, maximum, and safe pressures: [7] [6]

CartridgeUS designationNATO designationBulletRiflingThroatPressure in NATO chamberin 223 SAAMI chamberSafe sustained
223 Remington223 Rem55 gr FMJ1:14tight52,000 psi (359 MPa)52,000 psi (359 MPa)Yes
223 RemingtonM1935.56×45mm55 gr FMJ1:12tight55,000 psi (379 MPa)55,000 psi (379 MPa)Yes
223 RemingtonM1965.56×45mm54 gr Tracer1:12tight55,000 psi (379 MPa)55,000 psi (379 MPa)Yes
223 RemingtonM197C10524197-56-21:12tight70,000 psi (483 MPa)70,000 psi (483 MPa)One time only
5.56×45 mm NATOM855SS10962 gr ball1:7long62,366 psi (430 MPa) EPVATover 70,000 psi (483 MPa)No
5.56×45 mm NATOM856L11077 gr Tracer1:7long62,366 psi (430 MPa) EPVATover 70,000 psi (483 MPa)No
5.56×45 mm NATOM857SS111Tungsten carbide1:7long62,366 psi (430 MPa) EPVATover 70,000 psi (483 MPa)No
5.56×45 mm NATOProofProofunknown1:7long77,958 psi (538 MPa) EPVAT82,250 psi (567 MPa) estimatedNo

Beside the NATO EPVAT testing pressure testing protocols the other employed peak pressure measurement methodology or methodologies to correlate this table remain unknown.

Effects of barrel length on velocity

Barrel length helps determine a specific cartridge's muzzle velocity. A longer barrel typically yields a greater muzzle velocity, while a shorter barrel yields a lower one. The first AR-15 rifles used a barrel length of 20". In the case of the 223 Remington (M193), ammunition loses or gains about 25.7 ft/sec for each inch of barrel length, while 5.56×45 mm NATO (M855) loses or gains 30.3 ft/sec per inch of barrel length. [19]

Usage and commercial offerings

(Left to right) .223 Rem, .243 Win, .308 Win .223, .243, .308.JPG
(Left to right) .223 Rem, .243 Win, .308 Win

The .223 Remington has become one of the most popular cartridges and is currently used in a wide range of semiautomatic and manual-action rifles and even handguns, such as the Colt AR-15, Ruger Mini-14, Remington Model 700, Remington XP-100, etc. [20] [21] The popularity of .223 Remington is so great, that in the US it virtually eliminated all other similar .22 caliber center-fire varmint rifle cartridges. [22] [23]

It is commercially loaded with 0.224-inch (5.7 mm) diameter jacketed bullets, with weights ranging from 35 to 85 grains (2.27 to 5.8 g), with the most common loading by far being 55 gr (3.6 g). Ninety-grain and 95-grain Sierra Matchking bullets are available for reloaders. [24]

See also

Related Research Articles

<span class="mw-page-title-main">5.56×45mm NATO</span> Service rifle cartridge

The 5.56×45mm NATO is a rimless bottlenecked intermediate cartridge family developed in the late 1970s in Belgium by FN Herstal. It consists of the SS109, L110, and SS111 cartridges. On 28 October 1980 under STANAG 4172 it was standardized as the second standard service rifle cartridge for NATO forces as well as many non-NATO countries. Though they are not entirely identical, the 5.56×45mm NATO cartridge family was derived from and is dimensionally similar to the .223 Remington cartridge designed by Remington Arms in the early 1960s.

<span class="mw-page-title-main">.308 Winchester</span> Rimless, centerfire, bottlenecked rifle cartridge

The .308 Winchester is a smokeless powder rimless bottlenecked rifle cartridge.

6.8mm Remington SPC Intermediate rifle cartridge

The 6.8mm Remington Special Purpose Cartridge is a rimless bottlenecked intermediate rifle cartridge that was developed by Remington Arms in collaboration with members of the U.S. Army Marksmanship Unit and United States Special Operations Command to possibly replace the 5.56 NATO cartridge in Short Barreled Rifles (SBR) and Carbines. Based on the .30 Remington cartridge, it is midway between the 5.56×45mm NATO and 7.62×51mm NATO in bore diameter. It uses the same diameter bullet as the .270 Winchester hunting cartridge.

.300 Whisper

The .300 Whisper is a CIP standard cartridge in the Whisper family, a group of cartridges developed in the early 1990s by J.D. Jones of SSK Industries. It was developed as a multi-purpose cartridge, capable of utilizing relatively lightweight bullets at supersonic velocities as well as heavier bullets at subsonic velocities.

.257 Weatherby Magnum

The .257 Weatherby Magnum is a .257 caliber (6.53 mm) belted bottlenecked cartridge. It is one of the original standard length magnums developed by shortening the .375 H&H Magnum case to approx. 2.5 in (64 mm). Of the cartridges developed by Roy Weatherby, the .257 Weatherby Magnum was known to have been his favorite, and the cartridge currently ranks third in Weatherby cartridge sales, after the .30-378 Weatherby Magnum and the .300 Weatherby Magnum.

.222 Remington

The .222 Remington or 5.7×43mm (C.I.P), also known as the triple deuce, triple two, and treble two, is a centerfire rifle cartridge. Introduced in 1950, it was the first commercial rimless .22 (5.56 mm) cartridge made in the United States. As such, it was an entirely new design, without a parent case. The .222 Remington was a popular target cartridge from its introduction until the mid-1970s and still enjoys a reputation for accuracy. It remains a popular vermin or "varmint" cartridge at short and medium ranges with preferred bullet weights of 40–55 grains and muzzle velocities from 3,000 to 3,500 ft/s (915–1,067 m/s).

The .222 Remington Magnum was a short-lived commercially produced cartridge derived from the .222 Remington. Originally developed for a US military prototype Armalite AR-15 rifle in 1958, the cartridge was not adopted by the military, but was introduced commercially in sporting rifles.

7mm Remington Magnum

The 7mm Remington Magnum rifle cartridge was introduced as a commercially available round in 1962, along with the new Remington Model 700 bolt-action rifle. It is a member of the belted magnum family that is directly derived from the venerable .375 H&H Magnum. The original purpose of the belted magnum concept taken from the .300 H&H Magnum and .375 H&H Magnum, was to provide precise headspace control, since the sloping shoulders, while easing cartridge extraction, were unsuitable for this purpose. Improved cartridge extraction reliability is desirable while hunting dangerous game, in particular when a fast follow-up shot is required. The 7mm Remington Magnum is based on the commercial .264 Winchester Magnum, .338 Winchester Magnum, and .458 Winchester Magnum, which were based on the same belted .300 H&H Magnum and .375 H&H Magnum cases, trimmed to nearly the same length as the .270 Weatherby Magnum.

8mm Remington Magnum

The 8mm Remington Magnum belted rifle cartridge was introduced by Remington Arms Company in 1978 as a new chambering for the model 700 BDL rifle. The 8mm Remington Magnum's parent case is the .375 H&H Magnum. It is a very long and powerful cartridge that cannot be used in standard length actions, such as those that accommodate the .30-06 Springfield.

The .260 Remington cartridge was introduced by Remington in 1997. Many wildcat cartridges based on the .308 Winchester case had existed for years before Remington standardized this round.

.22 caliber, or 5.6 mm caliber, refers to a common firearms bore diameter of 0.22 inch (5.6 mm).

.416 Remington Magnum

The .416 Remington Magnum is a .416 caliber (10.57 mm) cartridge of belted bottlenecked design. The cartridge was intended as a dangerous game hunting cartridge and released to the public in 1989. The cartridge uses the case of the 8 mm Remington Magnum as a parent cartridge. When the cartridge was released in 1988, author Frank C. Barnes considered the .416 Remington Magnum to be the "most outstanding factory cartridge introduced in decades".

.284 Winchester

The .284 Winchester is a cartridge that has enjoyed a resurgence due to interest from long-range competitive shooters. Winchester has continued to produce brass cases for this since 1963. Introduced by Winchester in 1963, the .284 Winchester was designed to achieve .270 Winchester and .280 Remington performance from the new Winchester Model 100 autoloader and Winchester Model 88 lever-action rifles.

<span class="mw-page-title-main">6.5mm Creedmoor</span> Centerfire rifle cartridge

The 6.5mm Creedmoor (6.5×48 mm), designated 6.5 Creedmoor by SAAMI, 6.5 Creedmoor by the C.I.P. or 6.5 CM or 6.5 CRDMR for short, is a centerfire rifle cartridge introduced by Hornady in 2007. It was developed by Hornady senior ballistics scientist Dave Emary in partnership with Dennis DeMille, the vice-president of product development at Creedmoor Sports, hence the name. The cartridge is a necked-down modification of the .30 Thompson Center.

The 6×45mm is a rimless, bottlenecked cartridge based on the .223 Remington or 5.56 NATO cartridge necked up to .243 (6mm). The cartridge is also known as the 6mm-223 Remington or 6mm/223.

.300 AAC Blackout Rifle cartridge originally designed for use in the M4 carbine

The .300 AAC Blackout, also known as 7.62×35mm, is an intermediate cartridge developed in the United States by Advanced Armament Corporation (AAC) for use in the M4 carbine. The cartridge yields increased performance in shorter barrels and effective subsonic performance for suppressor use when compared to 5.56mm NATO. The 300 AAC Blackout utilizes standard 5.56mm NATO magazines and components with the exception of the barrel.

.223 Wylde chamber Hybrid rifle cartridge chamber

A .223 Wylde chamber is a hybrid rifle chamber designed to allow .22 caliber barrels to safely fire both .223 Remington and 5.56×45mm NATO ammunition. While the cartridge dimensions of both rounds are the same, 5.56 NATO loads produce pressures in excess of the .223 safe spec. The 5.56 chamber has angular differences that allow higher pressures safely. The .223 can be fired from a 5.56 chamber safely but with reduced accuracy. The Wylde is a hybrid chamber designed to allow both ammunition types to be safely fired with good accuracy.

The .277 Wolverine (6.8×39mm) is a wildcat cartridge. It is a multi-purpose mid-power cartridge with increased ballistic performance over the AR-15's traditional .223 Remington cartridge requiring only a new barrel to upgrade/convert any 5.56-based firearm to .277 Wolverine.

The 6 mm Advanced Rifle Cartridge (6×38mm), or 6mm ARC for short, is a 6mm (.243) caliber intermediate rifle cartridge introduced by Hornady in 2020, as a low-recoil, high-accuracy long-range cartridge designed for the AR-15 platform.


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