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Separated section on 243 Catbird as round is slightly different from 6mm-06. Added citations and background on 243 Catbird.
TXGRunner (talk | contribs)
69 edits
Corrected angle listed from 17 to 17.5 degrees
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'''[[.25-06 Remington|.25-06]]''' - necked down to accept a .25 bullet - The .25-06 was a wildcat cartridge for nearly 50 years before [[Remington Arms]] "tamed" it in 1969 through standardization and marketed the cartridge commercially as the .25-06 Remington.
'''[[.25-06 Remington|.25-06]]''' - necked down to accept a .25 bullet - The .25-06 was a wildcat cartridge for nearly 50 years before [[Remington Arms]] "tamed" it in 1969 through standardization and marketed the cartridge commercially as the .25-06 Remington.


'''6.5-06''' (or 6.5mm/06) - necked down to accept a 6.5&nbsp;mm bullet - The 6.5-06 offers ballistic performance between the commercialized .25-06 Remington and .270 Winchester with distinct advantages over both in particular long-range applications through a wide selection of bullets with high ballistic coefficients producing better extended range performance.<ref>{{cite book | last = Ackley | first = P.O. | title = Handbook for Shooters & Reloaders | edition = 12th Printing | series = vol I | origyear = 1962 | year = 1927 | publisher = Plaza Publishing | location = Salt Lake City, Utah | pages = 363–364| isbn = 978-99929-4-881-1}}</ref><ref name="TBR_6.5-06">{{cite web|title=.256 Newton and 6.5-06|url=https://www.ballisticstudies.com/Knowledgebase/.256+Newton+and+6.5-06.html|website=Terminal Ballistics Research|publisher=Terminal Ballistics Research|accessdate=22 March 2018}}</ref><ref>{{cite web|last1=Chuck|first1=Hawks|title=The 6.5mm-06 A-Square Rifle Cartridge|url=http://www.chuckhawks.com/6-5mm-06.htm|website=Guns & Shooting Online|publisher=Chuck Hawks|accessdate=22 March 2018}}</ref> This chambering was standardized as the [[6.5-06 A-Square]] with SAAMI in 1997 by the [[A-Square]] Company, a manufacturer of arms and ammunition based in the United States. Over 80 years earlier, a nearly identical cartridge was the commercially marketed as the [[.256 Newton]].<ref name="TBR_6.5-06" /> The .256 Newton suffered from a lack of slower burning powders capable of taking advantage of the large case capacity.<ref name="TBR_6.5-06" /> Munitions manufacturers ceased making the .256 Newton in 1938, 20 years after the firearms company built by [[Charles Newton (inventor)|Charles Newton]], who created the cartridge, went bankrupt.<ref name="TBR_6.5-06" /> There are small dimensional differences between the the .256 Newton and 6.5-06 later standardized by A-Square: the .256 Newton has an increased body taper, the shoulder is moved back, and has a sharper, 23 degree shoulder while the 6.5-06 has a 17 degree shoulder like the parent 30-06 case. As of March 2018, the 6.5-06 chambering is still listed with SAAMI.<ref>{{cite web|title=SAAMI 6_5-06 A-Square|url=http://www.saami.org/PubResources/_CC_Drawings/Rifle/6_5-06%20A-Square.pdf|website=Sporting Arms and Ammunition Manufacturers' Institute|publisher=SAAMI|accessdate=22 March 2018}}</ref>
'''6.5-06''' (or 6.5mm/06) - necked down to accept a 6.5&nbsp;mm bullet - The 6.5-06 offers ballistic performance between the commercialized .25-06 Remington and .270 Winchester with distinct advantages over both in particular long-range applications through a wide selection of bullets with high ballistic coefficients producing better extended range performance.<ref>{{cite book | last = Ackley | first = P.O. | title = Handbook for Shooters & Reloaders | edition = 12th Printing | series = vol I | origyear = 1962 | year = 1927 | publisher = Plaza Publishing | location = Salt Lake City, Utah | pages = 363–364| isbn = 978-99929-4-881-1}}</ref><ref name="TBR_6.5-06">{{cite web|title=.256 Newton and 6.5-06|url=https://www.ballisticstudies.com/Knowledgebase/.256+Newton+and+6.5-06.html|website=Terminal Ballistics Research|publisher=Terminal Ballistics Research|accessdate=22 March 2018}}</ref><ref>{{cite web|last1=Chuck|first1=Hawks|title=The 6.5mm-06 A-Square Rifle Cartridge|url=http://www.chuckhawks.com/6-5mm-06.htm|website=Guns & Shooting Online|publisher=Chuck Hawks|accessdate=22 March 2018}}</ref> This chambering was standardized as the [[6.5-06 A-Square]] with SAAMI in 1997 by the [[A-Square]] Company, a manufacturer of arms and ammunition based in the United States. Over 80 years earlier, a nearly identical cartridge was the commercially marketed as the [[.256 Newton]].<ref name="TBR_6.5-06" /> The .256 Newton suffered from a lack of slower burning powders capable of taking advantage of the large case capacity.<ref name="TBR_6.5-06" /> Munitions manufacturers ceased making the .256 Newton in 1938, 20 years after the firearms company built by [[Charles Newton (inventor)|Charles Newton]], who created the cartridge, went bankrupt.<ref name="TBR_6.5-06" /> There are small dimensional differences between the the .256 Newton and 6.5-06 later standardized by A-Square: the .256 Newton has an increased body taper, the shoulder is moved back, and has a sharper, 23 degree shoulder while the 6.5-06 has a 17.5 degree shoulder like the parent 30-06 case. As of March 2018, the 6.5-06 chambering is still listed with SAAMI.<ref>{{cite web|title=SAAMI 6_5-06 A-Square|url=http://www.saami.org/PubResources/_CC_Drawings/Rifle/6_5-06%20A-Square.pdf|website=Sporting Arms and Ammunition Manufacturers' Institute|publisher=SAAMI|accessdate=22 March 2018}}</ref>


'''7mm-06''' - necked down to accept a 7mm bullet - Originated during experimentation with 7mm bullets in inexpensive, surplus .30-06 brass cases.<ref name="speer">Speer, Raymond G. ''Wildcat Rifle Loads'' (Speer Products Company, 1956<!--city?-->) p.81</ref> 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 (firearms)|headspace]] extended slightly more than one millimeter (.05 inch) to prevent chambering in .270 Winchester rifles.<ref>{{Cite book|title=Handloading|last=Davis|first=William C. Jr.|publisher=National Rifle Association|year=1981|isbn=0-935998-34-9|location=|pages=180–181|via=}}</ref> Early Remington in-house developmental rounds were headstamped R-P 7MM-06 REM but, to avoid confusion with similarly named wildcats, the headstamp was changed to 280 REM.{{citation needed|date=March 2018}}
'''7mm-06''' - necked down to accept a 7mm bullet - Originated during experimentation with 7mm bullets in inexpensive, surplus .30-06 brass cases.<ref name="speer">Speer, Raymond G. ''Wildcat Rifle Loads'' (Speer Products Company, 1956<!--city?-->) p.81</ref> 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 (firearms)|headspace]] extended slightly more than one millimeter (.05 inch) to prevent chambering in .270 Winchester rifles.<ref>{{Cite book|title=Handloading|last=Davis|first=William C. Jr.|publisher=National Rifle Association|year=1981|isbn=0-935998-34-9|location=|pages=180–181|via=}}</ref> Early Remington in-house developmental rounds were headstamped R-P 7MM-06 REM but, to avoid confusion with similarly named wildcats, the headstamp was changed to 280 REM.{{citation needed|date=March 2018}}

Revision as of 21:25, 27 March 2018

Parent Cartridge .30-06 Springfield
From left: .25-06, .270 Win, .280 Rem, .30-06, .35 Whelen
TypeRifle
Service history
In service1906
Used byUSA and others
WarsWorld War I, World War II, Korean War, Vietnam War
Production history
DesignerUnited States Military
Designed1906
Produced1906-present
Specifications
Parent case.30-03
Case typeRimless, bottleneck
Bullet diameter7.62 mm (0.300 in)
Neck diameter8.63 mm (0.340 in)
Shoulder diameter11.20 mm (0.441 in)
Base diameter11.96 mm (0.471 in)
Rim diameter12.01 mm (0.473 in)
Rim thickness1.24 mm (0.049 in)
Case length63.35 mm (2.494 in)
Overall length84.84 mm (3.340 in)
Case capacity4.43 cm3 (68.4 gr H2O)
Rifling twist254 mm (1 in 10 in)
Primer typeLarge rifle
Maximum pressure405 MPa (58,700 psi)
Ballistic performance
Bullet mass/type Velocity Energy
150 gr (10 g) Nosler Ballistic Tip 2,910 ft/s (890 m/s) 2,820 ft⋅lbf (3,820 J)
165 gr (11 g) BTSP 2,800 ft/s (850 m/s) 2,872 ft⋅lbf (3,894 J)
180 gr (12 g) Core-Lokt Soft Point 2,700 ft/s (820 m/s) 2,913 ft⋅lbf (3,949 J)
200 gr (13 g) Partition 2,569 ft/s (783 m/s) 2,932 ft⋅lbf (3,975 J)
220 gr (14 g) RN 2,500 ft/s (760 m/s) 2,981 ft⋅lbf (4,042 J)
Test barrel length: 24 inch
Source(s): Federal Cartridge[1] / Accurate Powder[2]

Wildcat cartridges are firearms cartridges whose dimensions are not standardized with recognized small arms standardization bodies like the Sporting Arms and Ammunition Manufacturers' Institute (SAAMI) and the Commission internationale permanente pour l'épreuve des armes à feu portatives (CIP).[3][4][5] The majority of wildcat chamberings are modified versions of standardized commercial or military cartridges referred to as the "parent" of the wildcat.[5] Developers, or "wildcatters," modify standard cartridges in an attempt to improve performance in specific areas.[5] This article deals with wildcat cartridges developed from the .30-06 Springfield cartridge through narrowing or widening the cartridge neck (necking up or down) the original case to fit a smaller or larger bullet and where the overall case length is kept essentially the same.

Wildcats

.22-06 (also .223-06) - necked down to accept a .224 caliber bullet - The .22-06 uses the same caliber bullet as the .223 Remington. This round is frequently used for varmint hunting, offering the shooter a long range, high-velocity, and therefore flat shooting, chambering suitable for that sport. The similar .226 Express, in addition to reducing neck diameter, reduces shoulder diameter to impose a long, slender body taper on the .30-06 case.[6] Extensive experimentation during the mid-20th century indicated no practical benefit from the incremental volume increase of the 63 mm-long .30-06 case over the 57 mm-long 7mm Mauser case for .22 caliber bullets.[7]

6mm-06 (also .243-06) - necked down to accept a .243 bullet - Once considered significantly overbore, proponents of the 6mm-06 chambering argue the cartridge is more practical following the development and availability of slower burning powders capable of exploiting the larger case capacity.[8][9] The cartridge has greater capacity than either the .243 Winchester or the 6mm Remington, slightly more capacity than the .240 Weatherby Magnum, and slightly less capacity than 6mm-284 wildcat cartridge.[9] The 6mm-06 can drive a 105 grain .243 caliber projectile in excess of 3200 feet per second (fps), giving the 6mm-06 a ballistic advantage over the non-magnum .243 offerings from Winchester and Remington, particularly at longer ranges.[8] [9] Due to the wide availability of inexpensive parent cases, the 6mm-06 is also less expensive than comparable long-range performers like the .240 Weatherby Magnum and the 6mm-284.[8] [9]

.243 Catbird - .270 Winchester necked down to a .243 bullet with the shoulder blown out (angle increased) to 35 degrees - The .270 Winchester is a standardized cartridge of the same design as the .30-06 except the case is 1.2mm longer and necked down to the .270 caliber. Therefore, the .243 Catbird is a 6mm-06 with a 35 degree shoulder and a 1.2mm longer case.[10] The .243 Catbird was developed by Kenny Jarrett of Jarrett Rifles to achieve 4000 fps with a 68-70 grain bullet.[10][11] Actual performance tests showed the cartridge achieved 4100 fps with a 70 grain bullet, 3800 fps with an 85 grain bullet, and 3500 fps with a 95 grain projectile.[10] Jarret describes the chambering as a "barrel burner" with a barrel maintaining accuracy for about 1500 rounds.[10]

.25-06 - necked down to accept a .25 bullet - The .25-06 was a wildcat cartridge for nearly 50 years before Remington Arms "tamed" it in 1969 through standardization and marketed the cartridge commercially as the .25-06 Remington.

6.5-06 (or 6.5mm/06) - necked down to accept a 6.5 mm bullet - The 6.5-06 offers ballistic performance between the commercialized .25-06 Remington and .270 Winchester with distinct advantages over both in particular long-range applications through a wide selection of bullets with high ballistic coefficients producing better extended range performance.[12][13][14] This chambering was standardized as the 6.5-06 A-Square with SAAMI in 1997 by the A-Square Company, a manufacturer of arms and ammunition based in the United States. Over 80 years earlier, a nearly identical cartridge was the commercially marketed as the .256 Newton.[13] The .256 Newton suffered from a lack of slower burning powders capable of taking advantage of the large case capacity.[13] Munitions manufacturers ceased making the .256 Newton in 1938, 20 years after the firearms company built by Charles Newton, who created the cartridge, went bankrupt.[13] There are small dimensional differences between the the .256 Newton and 6.5-06 later standardized by A-Square: the .256 Newton has an increased body taper, the shoulder is moved back, and has a sharper, 23 degree shoulder while the 6.5-06 has a 17.5 degree shoulder like the parent 30-06 case. As of March 2018, the 6.5-06 chambering is still listed with SAAMI.[15]

7mm-06 - necked down to accept a 7mm bullet - Originated during experimentation with 7mm bullets in inexpensive, surplus .30-06 brass cases.[16] 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.[17] Early Remington in-house developmental rounds were headstamped R-P 7MM-06 REM but, to avoid confusion with similarly named wildcats, the headstamp was changed to 280 REM.[citation needed]

8mm-06 - necked up to accept an 8mm bullet - The 8mm-06 allows owners of military surplus 7.92×57mm Mauser rifles to fire 8mm bullets using inexpensive, surplus .30-06 brass cases without rebarreling their rifle, only a rechambering is necessary.[16]

.338-06 - necked up to accept a .338 bullet - The 338-06 gives shooters the option of using heavier bullets for bigger game while suffering less recoil than other .338 cartridges. The .338-06 chambering was a popular wildcat dating back to the late 1950's.[18][19] The cartridge was standardized as the 338-06 A-Square with SAAMI in 1998 by the A-Square Company.[18][19] Weatherby briefly offered some models of rifles chambered in 338-06 A-Square.[18][19] The 338-06 is a practical, flexible, and potent medium bore cartridge offering substantially similar performance to the prototype 338 Winchester Short Magnum later released as the .325 Winchester Short Magnum while producing less stress on the bullet and shooter than a magnum cartridge. As of March 2018, the chambering was still listed with SAAMI.[20]

.35-06 - necked up to accept a .35 bullet - Now standardized and marketed as the .35 Whelen, this cartridge was intended to create a cartridge suitable for bigger and potentially dangerous game, specifically African game, on standard length actions with relatively inexpensive components (i.e. 30-06 brass cases).[21]

.375-06 - necked up to accept a .375 bullet - Also known as the .375 Whelen, this wildcat was another effort to use standard actions and inexpensive, surplus cases with heavier bullets.[citation needed] The .375 Whelen Improved sharpens the .30-06 shoulder for more reliable headspace.[citation needed]

.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.[22]

Ackley Improved - P.O. Ackley was a notable gunsmith famous for developing wildcat cartridges from parent cartridges like the .30-06 Springfield. For many of the wildcats listed above, and several of standardized commercial chamberings based on the .30-06 cartridge, there are "Ackley Improved" versions with sharper shoulders increasing case capacity.[23] These versions are noted by the letters "AI" after the cartridge name (e.g. 6.5-06 AI, 30-06 AI, etc.).[23]

Gibbs Cartridges - R.E. "Rocky" Gibbs was a firearms experimenter and gunsmith based in Viola, Idaho in the 1950s.[5] He developed a series of improved cartridges for chamberings derived from the .30-06 Springfield, including the .25 Gibbs, 6.5mm Gibbs, 270 Gibbs, 7mm Gibbs, .30 Gibbs, and 8mm Gibbs by blowing out the case, pushing the shoulder forward, and increasing the angle of the shoulder.[5]

Parent cartridge

The .30-06 Springfield cartridge (pronounced “thirty-aught-six”, "thirty-oh-six") or 7.62×63mm in metric notation, was introduced to the United States Army 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 7.62×51mm NATO (commercial .308 Winchester) and 5.56×45mm 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.

Parent cartridge dimensions

The .30-06 Springfield has a 68.2 grains (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 guns alike, under extreme conditions.

.30-06 Springfield maximum C.I.P. cartridge dimensions. All sizes in millimeters (mm).

See also

References

  1. ^ "Federal Cartridge Co. ballistics page". Archived from the original on 22 September 2007. Retrieved 2007-09-21. {{cite web}}: Unknown parameter |deadurl= ignored (|url-status= suggested) (help)
  2. ^ "Accurate Powder reload data table" (PDF). Archived from the original (PDF) on 20 March 2009. Retrieved 2009-02-09. {{cite web}}: Unknown parameter |deadurl= ignored (|url-status= suggested) (help)
  3. ^ "Small Arms and Ammunition Manufacturers' Institute". Small Arms and Ammunition Manufacturers' Institute. Small Arms and Ammunition Manufacturers' Institute. Retrieved 24 March 2018.
  4. ^ "Commission internationale permanente pour l'épreuve des armes à feu portatives". Commission internationale permanente pour l'épreuve des armes à feu portatives. Commission internationale permanente pour l'épreuve des armes à feu portatives. Retrieved 24 March 2018.
  5. ^ a b c d e Frank C. Barnes; M.L. McPherson, eds. (1997). Cartridges of the world (8th, rev. and expanded ed.). Northbrook, IL: DBI Books. ISBN 978-0-87349-178-5.
  6. ^ Sharpe, Philip B. Complete Guide To Handloading (Funk & Wagnalls, 1953 ), p.351.
  7. ^ Landis, Charles S. Twenty-Two Caliber Varmint Rifles (Small Arms Technical Publishing Company, 1947)) p.81
  8. ^ Davis, William C. Jr. (1981). Handloading. National Rifle Association. pp. 180–181. ISBN 0-935998-34-9.
  9. ^ a b c Chuck, Hawks. "The .338-06 A-Square". Guns & Shooting Online. Chuck Hawks. Retrieved 22 March 2018.
  10. ^ a b c ".338-06 A-Square". Terminal Ballistics Research. Terminal Ballistics Research. Retrieved 22 March 2018.
  11. ^ "SAAMI 338-06 A-SQUARE" (PDF). Sporting Arms and Ammunition Manufacturers' Institute. SAAMI. Retrieved 22 March 2018.
  12. ^ Speer Reloading Manual (8 ed.). Lewiston, Idaho: Speer Products Company. 1970. p. 305, 306. ISBN ASIN B000VXVJJM. {{cite book}}: |access-date= requires |url= (help); Check |isbn= value: invalid character (help)
  13. ^ Sharpe, Philip B. Complete Guide To Handloading (Funk & Wagnalls, 1953) pp.206&398
  14. ^ a b Ackley, P.O. "P.O. Ackley: His Life and Work". Ackley Improved. Estate of P.O. Ackley. Retrieved 24 March 2018.
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