.30-06 Springfield Wildcat Cartridges
Encyclopedia
Wildcat cartridge
s are firearms cartridges whose dimensions have been modified. Usually these modifications are with an eye toward improved performance, either measurable or not. This article deals with wildcat cartridges which result from a simple necking down or up of the original .30-06 Springfield
where the overall case length is kept essentially the same. Many of these wildcats were more stages in the development of modern wildcat cartridges than they were a serious chambering in their own right.
.20-06 - necked down to accept a .20 Cal bullet - Like the .17-06 the drawbacks of this wildcat make it an unreasonable cartridge.
.22-06 (alternately .223-06) - necked down to accept a .224 Caliber bullet similar to the popular .223 Remington
. Due to the wide availability of .224 bullets this wildcat is rumored to have be incepted so that a barrel switch will let a familiar or comfortable rifle be used for varmint hunting. The similar .226 Express not only reduces neck diameter, but also reduces shoulder diameter to impose a long, slender body taper on the .30-06 case. Extensive experimentation during the mid-20th century indicated no practical benefit from the incremental volume the 63 mm .30-06 case over the 57 mm 7mm Mauser case for .22 caliber bullets.
.243-06 (alternately 6mm-06) - necked down to accept a .243 bullet - With the rising popularity of the .243 as a light deer rifle this wildcat is affordable to reload and offers lightened recoil .
.25-06 - necked down to accept a .25 bullet - Originally a wildcat this cartridge is now commercially available
.
6.5-06 (alternately 6.5mm/06) - necked down to accept a 6.5 mm bullet - Very similar performance to the now commercialized .25-06.
.270-06 - necked down to accept a .270 bullet - This is essentially the .270 Winchester
; although commercial cartridges use the slightly longer 65 mm .30-03
case from which the .30-06 was derived. Firing necked down .270-06 cases in a .270 Winchester may cause chamber erosion.
7mm-06 - necked down to accept a 7mm bullet - Originated during experimentation with the ballistic possibilities of popular 7mm bullets in plentiful .30-06 brass cases. The commercial .280 Remington
(or 7mm Express Remington) is very similar, but uses the slightly longer 65 mm .30-03 case with the shoulder headspace extended slightly more than one millimeter (.05 inch) to prevent chambering in .270 Winchester rifles.
.303-06 - necked up to accept a .303 bullet - May have originated in markets where, at one time, the .303 bullet was easier to get.
8mm-06 - necked up to accept an 8mm bullet for improved ballistics using plentiful .30-06 brass cases in re-chambered military surplus 7.92x57mm Mauser
rifles.
.338-06
- necked up to accept a .338 bullet - An effort to provide heavier bullets for bigger game with less recoil than other .338 offerings.
.35-06 - necked up to accept a .35 bullet - A successful effort to use heavier bullets for bigger game. Now commercialized as the .35 Whelen
.
.375-06 - necked up to accept a .375 bullet - Also known as the .375 Whelen
, it is another effort to use heavier bullets with plentiful actions and cases. The .375 Whelen Improved sharpens the .30-06 shoulder for more reliable headspace.
.400-06 - necked up to accept a .405 Winchester
bullet - Better known as the .400 Whelen
. Griffin & Howe chambered rifles for this cartridge, but headspace difficulties were reported with the small shoulder.
in 1906 (hence “06”) and standardized, used until the 1960s and early 1970s. It replaced the .30-03
, 6 mm Lee Navy
and .30 US Army
(also called .30-40 Krag). The .30-06 remained the US Army's primary rifle cartridge for nearly 50 years before it was finally replaced by the 7.62 x 51 mm NATO (commercial .308 Winchester
) and 5.56x45mm NATO
(commercial .223 Remington
), both of which remain in current U.S. and NATO service. It remains a very popular sporting round, with ammunition produced by all major manufacturers.
(4.43 ml
) H2O cartridge case capacity. The exterior shape of the case was designed to promote reliable case feeding and extraction in bolt action rifles and machine gun
s alike, under extreme conditions.
.30-06 Springfield maximum C.I.P. cartridge dimensions. All sizes in millimeters (mm).
Wildcat cartridge
A wildcat cartridge, or wildcat, is a custom cartridge for which ammunition and firearms are not mass produced. These cartridges are often created in order to optimize a certain performance characteristic of an existing commercial cartridge.Developing and using wildcat cartridges does not...
s are firearms cartridges whose dimensions have been modified. Usually these modifications are with an eye toward improved performance, either measurable or not. This article deals with wildcat cartridges which result from a simple necking down or up of the original .30-06 Springfield
.30-06 Springfield
The .30-06 Springfield cartridge or 7.62×63mm in metric notation, was introduced to the United States Army in 1906 and standardized, and was in use until the 1960s and early 1970s. It replaced the .30-03, 6 mm Lee Navy, and .30 US Army...
where the overall case length is kept essentially the same. Many of these wildcats were more stages in the development of modern wildcat cartridges than they were a serious chambering in their own right.
Wildcats
.17-06 - necked down to accept a .17 Cal bullet - Appears to be mostly a rumor or joke as limited bullet availability, extreme case pressure and no ballistic benefit make it all but useless..20-06 - necked down to accept a .20 Cal bullet - Like the .17-06 the drawbacks of this wildcat make it an unreasonable cartridge.
.22-06 (alternately .223-06) - necked down to accept a .224 Caliber bullet similar to the popular .223 Remington
.223 Remington
The .223 Remington is a sporting cartridge with almost the same external dimensions as the 5.56×45mm NATO military cartridge. The name is commonly pronounced either two-two-three or two-twenty-three. It is loaded with a diameter, jacketed bullet, with weights ranging from , though the most common...
. Due to the wide availability of .224 bullets this wildcat is rumored to have be incepted so that a barrel switch will let a familiar or comfortable rifle be used for varmint hunting. The similar .226 Express not only reduces neck diameter, but also reduces shoulder diameter to impose a long, slender body taper on the .30-06 case. Extensive experimentation during the mid-20th century indicated no practical benefit from the incremental volume the 63 mm .30-06 case over the 57 mm 7mm Mauser case for .22 caliber bullets.
.243-06 (alternately 6mm-06) - necked down to accept a .243 bullet - With the rising popularity of the .243 as a light deer rifle this wildcat is affordable to reload and offers lightened recoil .
.25-06 - necked down to accept a .25 bullet - Originally a wildcat this cartridge is now commercially available
.25-06 Remington
The .25-06 Remington had been a wildcat cartridge for half a century before being standardized by Remington in 1969. It is based on the .30-06 Springfield cartridge necked-down to .257 inch caliber with no other changes...
.
6.5-06 (alternately 6.5mm/06) - necked down to accept a 6.5 mm bullet - Very similar performance to the now commercialized .25-06.
.270-06 - necked down to accept a .270 bullet - This is essentially the .270 Winchester
.270 Winchester
The .270 Winchester was developed by Winchester Repeating Arms Company in 1923 and unveiled in 1925 as a chambering for their bolt-action Model 54. The cartridge is based upon the .30-06 Springfield...
; although commercial cartridges use the slightly longer 65 mm .30-03
.30-03
The .30-03 was a short-lived cartridge developed by the United States in 1903, to replace the .30-40 Krag in the new Springfield 1903 rifle. The .30-03 was also called the .30-45, since it used a 45 grain powder charge; the name was changed to .30-03 to indicate the year of adoption. It used a...
case from which the .30-06 was derived. Firing necked down .270-06 cases in a .270 Winchester may cause chamber erosion.
7mm-06 - necked down to accept a 7mm bullet - Originated during experimentation with the ballistic possibilities of popular 7mm bullets in plentiful .30-06 brass cases. The commercial .280 Remington
.280 Remington
The .280 Remington, also known as the 7 mm Express Remington, was introduced in 1957 for the Remington model 740, 760, 721 and 725 rifles. The .280 is based on the .30-06 Springfield necked down to accept 7 mm bullets, with the neck moved forward .050in...
(or 7mm Express Remington) is very similar, but uses the slightly longer 65 mm .30-03 case with the shoulder headspace extended slightly more than one millimeter (.05 inch) to prevent chambering in .270 Winchester rifles.
.303-06 - necked up to accept a .303 bullet - May have originated in markets where, at one time, the .303 bullet was easier to get.
8mm-06 - necked up to accept an 8mm bullet for improved ballistics using plentiful .30-06 brass cases in re-chambered military surplus 7.92x57mm Mauser
7.92x57mm Mauser
The 8×57mm IS is a rimless bottlenecked rifle cartridge. The 8×57mm IS was adopted by the German Empire in 1905, and was the German service cartridge in both World Wars...
rifles.
.338-06
.338-06
The .338-06 is a wildcat cartridge based on the .30-06. It allows heavier .338 caliber bullets to be used from the .30-06 non-belted case. This is a better choice for heavy bodied game such as moose, elk, and brown bear than the .30-06...
- necked up to accept a .338 bullet - An effort to provide heavier bullets for bigger game with less recoil than other .338 offerings.
.35-06 - necked up to accept a .35 bullet - A successful effort to use heavier bullets for bigger game. Now commercialized as the .35 Whelen
.35 Whelen
The .35 Whelen is a powerful medium-bore rifle cartridge that does not require a magnum action or a magnum bolt-face. The parent of this cartridge is the .30-06 Springfield, which is necked-up to accept a bullet diameter of...
.
.375-06 - necked up to accept a .375 bullet - Also known as the .375 Whelen
.375 Whelen (.375-06)
The .375 Whelen cartridge was developed in 1951 by L.R. "Bob" Wallack and named in honor of Colonel Townsend Whelen. It is a .30-06 Springfield case necked up to .375. While the .375 Whelen retains the .30-06's shoulder angle of 17° 30′, an improved version was introduced with a...
, it is another effort to use heavier bullets with plentiful actions and cases. The .375 Whelen Improved sharpens the .30-06 shoulder for more reliable headspace.
.400-06 - necked up to accept a .405 Winchester
.405 Winchester
The .405 Winchester is a centerfire rifle cartridge introduced in 1904 for the Winchester 1895 lever-action rifle. It was the most powerful lever-action cartridge available until the .444 Marlin was introduced in 1964, and was highly regarded by U.S. President Theodore Roosevelt during his safari...
bullet - Better known as the .400 Whelen
.400 Whelen
The .400 Whelen cartridge was developed by Colonel Townsend Whelen while he was commanding officer of Frankford Arsenal in the early 1920s. The cartridge resembles a .30-06 Springfield case necked up to .40 caliber to accept bullets manufactured for the .405 Winchester.-Design:Colonel Whelen...
. Griffin & Howe chambered rifles for this cartridge, but headspace difficulties were reported with the small shoulder.
Parent cartridge
The .30-06 Springfield cartridge or 7.62 x 63 mm in metric notation, was introduced to the United States ArmyUnited States Army
The United States Army is the main branch of the United States Armed Forces responsible for land-based military operations. It is the largest and oldest established branch of the U.S. military, and is one of seven U.S. uniformed services...
in 1906 (hence “06”) and standardized, used until the 1960s and early 1970s. It replaced the .30-03
.30-03
The .30-03 was a short-lived cartridge developed by the United States in 1903, to replace the .30-40 Krag in the new Springfield 1903 rifle. The .30-03 was also called the .30-45, since it used a 45 grain powder charge; the name was changed to .30-03 to indicate the year of adoption. It used a...
, 6 mm Lee Navy
M1895 Lee Navy
The Lee Model 1895 was a straight-pull, cam-action magazine rifle adopted in limited numbers by the U.S. Navy and Marine Corps in 1895 as a first-line infantry rifle...
and .30 US Army
.30-40 Krag
The .30-40 Krag was a cartridge developed in the early 1890s to provide the U.S. armed forces with a smokeless powder cartridge suited for use with modern small-bore repeating rifles to be selected in the 1892 small arm trials...
(also called .30-40 Krag). The .30-06 remained the US Army's primary rifle cartridge for nearly 50 years before it was finally replaced by the 7.62 x 51 mm NATO (commercial .308 Winchester
.308 Winchester
The .308 Winchester is a rifle cartridge and is the commercial cartridge upon which the military 7.62x51mm NATO centerfire cartridge is based. The .308 Winchester was introduced in 1952, two years prior to the NATO adoption of the 7.62x51mm NATO T65...
) and 5.56x45mm NATO
5.56x45mm NATO
5.56×45mm NATO is a rifle cartridge developed in the United States and originally chambered in the M16 rifle. Under STANAG 4172, it is a standard cartridge for NATO forces as well as many non-NATO countries. It is derived from, but not identical to, the .223 Remington cartridge...
(commercial .223 Remington
.223 Remington
The .223 Remington is a sporting cartridge with almost the same external dimensions as the 5.56×45mm NATO military cartridge. The name is commonly pronounced either two-two-three or two-twenty-three. It is loaded with a diameter, jacketed bullet, with weights ranging from , though the most common...
), both of which remain in current U.S. and NATO service. It remains a very popular sporting round, with ammunition produced by all major manufacturers.
Parent cartridge dimensions
The .30-06 Springfield has a 68.2 grainsGrain (measure)
A grain is a unit of measurement of mass that is nominally based upon the mass of a single seed of a cereal. From the Bronze Age into the Renaissance the average masses of wheat and barley grains were part of the legal definition of units of mass. However, there is no evidence of any country ever...
(4.43 ml
Litre
pic|200px|right|thumb|One litre is equivalent to this cubeEach side is 10 cm1 litre water = 1 kilogram water The litre is a metric system unit of volume equal to 1 cubic decimetre , to 1,000 cubic centimetres , and to 1/1,000 cubic metre...
) H2O cartridge case capacity. The exterior shape of the case was designed to promote reliable case feeding and extraction in bolt action rifles and machine gun
Machine gun
A machine gun is a fully automatic mounted or portable firearm, usually designed to fire rounds in quick succession from an ammunition belt or large-capacity magazine, typically at a rate of several hundred rounds per minute....
s alike, under extreme conditions.
.30-06 Springfield maximum C.I.P. cartridge dimensions. All sizes in millimeters (mm).
See also
- Hydrostatic shockHydrostatic shockHydrostatic shock or hydraulic shock describes the observation that a penetrating projectile can produce remote wounding and incapacitating effects in living targets through a hydraulic effect in their liquid-filled tissues, in addition to local effects in tissue caused by direct impact...
- Caliber conversion sleeveCaliber conversion sleeveA caliber conversion sleeve is a device which can be used to non-permanently alter a firearm to allow it to fire a different cartridge than the one it was originally designed to...
- List of rifle cartridges
- Table of pistol and rifle cartridges
- 7 mm caliber7 mm caliberThis article lists firearm cartridges which have a bullet in the to caliber range.*Length refers to the cartridge case length.*OAL refers to the overall length of the cartridge....
- .303 British.303 British.303 British, or 7.7x56mmR, is a .311 inch calibre rifle and machine gun cartridge first developed in Britain as a blackpowder round put into service in December 1888 for the Lee-Metford rifle, later adapted to use smokeless powders...
- Delta L problemDelta L problemThe delta L problem is a condition that occurs regarding certain firearms chambers and their practical incompatibility with ammunition made for the corresponding chambering....
- sectional densitySectional densitySectional density is the ratio of an object's mass to its cross-sectional area. It conveys how well an object's mass is distributed to overcome resistance. For illustration, a needle can penetrate a target medium with less force than a coin of the same mass...