7-30 Waters Explained

7-30 Waters
Origin:United States
Type:Rifle and single shot handgun
Designer:Ken Waters
Design Date:1976
Production Date:1984–present
Parent:.30-30 Winchester
Case Type:Rimmed, bottleneck
Bullet:.284
Bullet Ref:[1]
Land:.277
Neck:.306
Base:.422
Rim Dia:.506
Rim Thick:.058
Case Length:2.04
Length:2.52
Primer:Large rifle
Max Pressure:45000
Max Cup:40,000
Bw1:120
Btype1:Nosler Partition FP
Vel1:2700
En1:1940
Bw2:139
Btype2:Flat point
Vel2:2540
En2:1990
Bw3:154
Btype3:Round nose
Vel3:2347
En3:1835
Test Barrel Length:24"
Balsrc:Cartridges of the World, 10th Ed., Barnes

The 7-30 Waters cartridge was originally a wildcat cartridge developed by author Ken Waters in 1976 to give better performance to lever-action rifle shooters than the parent .30-30 Winchester cartridge, by providing a higher velocity and flatter trajectory with a smaller, lighter bullet. By 1984, Winchester introduced a Model 94 rifle chambered for the 7-30 Waters, establishing it as a commercial cartridge. In 1986, Thompson/Center began chambering 10-inch, 14-inch, and 20-inch Contender barrels for the cartridge.[2]

Development

A review of the 7-08 Rem. (a .308 Win. case necked down to 7 mm), explains the design of the cartridge with the following:

There are two primary reasons a 7 mm recoils less than an comparably effective .30 cal. cartridge: To match the 7 mm's ballistic coefficient requires a significantly heavier .30 cal bullet; and to drive that heavier .30 cal bullet at similar velocities (for kinetic energy and wind resistance ("time-to-target")), requires more powder. This combination of heavier bullets with heavier powder charges significantly increases the recoil of the .30 caliber.

The .30-30 Winchester is typically limited to short ranges, primarily because of the relatively small case capacity and the 150-grain and 170-grain bullet weights. To compensate for this, Waters necked the cartridge down to use a 7 mm bullet (.284 inches), rather than the original .308 caliber (7.62 mm) bullet. Because it was designed to function in lever-action rifles, the 7-30 maintained the same low working pressure, yet Waters' original design fired a lighter bullet (139 grains) at a higher velocity (2600 ft/s).[3] A typical .30-30 factory load fires a 150-grain bullet at 2390 ft/s, while the current 7-30 factory load fires a 120-grain bullet at 2700 ft/s. Muzzle energy is just over 1900 ft-lbs for both of these loads, but the lighter weight 7 mm bullet has a higher velocity and flatter trajectory.

Ammunition

Lever-action rifles with tubular magazines can only safely use spitzer bullets as the first cartridge in the chamber with only flat-pointed bullets in the magazine, or if the rifle is used as a 2-shot (1 cartridge in the chamber and only 1 in the magazine).

Handloaders for single-shot 7-30 Waters rifles or pistols are not limited to flat-nosed bullets and thus have a wide range manufacturers and weights of 7mm pointed bullets from which to choose.

Manufactured ammunition

Federal Cartridge offers manufactured 7-30 Waters cartridges—the Federal Premium Vital-Shok firing a 120-grain (7.78 g) Sierra GameKing boat-tail soft-point flat-nose bullet at 2700 ft/s with 1940 ft-lbs of energy.[4] It has a sectional density of 0.213

Hornady Manufacturing Company's 2020 new products catalog does show 7-30 Waters LEVERevolution ammunition which would allow the safe use of pointed, ballistically efficient spitzer bullets in tubular magazines.[5]

Handloading

Speer Bullets offers a 130 gr (8.42 gr), copper-jacketed soft-point flat-nosed bullet for use in lever-action rifles. It has a sectional density of 0.23 and a ballistic coefficient of 0.257[6]

Hornady Manufacturing Company now offers a 120 grain FTX bullet in 7mm/.284" caliber.[7] [8] This allows the safe use of pointed, ballistically efficient spitzer bullets in tubular magazines.

Firearms

Rifles

By 1982, Waters had perfected his new cartridge, firing a 139-grain flat-point bullet at a muzzle velocity of 2600 ft/s from a lever-action rifle with a 24" barrel. By 1983, he had managed to attract the attention of Winchester, which led to the introduction of the Model 94 angle eject 20" barreled carbine and Model 94XTR angle eject 24" barreled rifle in the new caliber in 1984. After 13 years, production ceased in 1997.

Thompson Center Arms' single-shot Contender and Encore rifles are both offered in 7-30 Waters in either stainless steel or blued steel through their custom shop.[9]

Handguns

Thompson Center Arms began to chamber the 7-30 Waters in their Contender single shot pistol starting in 1986. Factory loads are capable of velocities of 2400 ft/s from the 14" pistol barrel, making the 7-30 Waters one of the fastest commercial rounds available for the pistol. In addition, the single shot Contender and Encore pistols can safely use pointed bullets, which allows the handloader to gain additional retained velocity at long ranges for uses such as handgun hunting and metallic silhouette shooting.

Usage

Paco Kelly, of leverguns.com:

Bullets in the 110- to 120-grain range are suitable for small game and varmints (handloads with 110s can nearly achieve 3000 ft/s); 120- to 154-grain range for deer; and 154 to 168 gr range are adequate for larger game at closer ranges.[10] "The 7-30 Waters has proven its capabilities in the field on big game weighing up to 300 pounds at woods ranges. As this is written, two bullets of flat nose form are available to handloaders for use in rifles with tubular magazines. For whitetails, the 120-grain Nosler is an excellent performer, but when greater penetration is needed for Mule Deer and Black Bear, the 139-grain Hornady is a better choice."[11] Nosler and Hornady no longer offer flat nose bullets in 7mm.[12] [13]

Best performance is had with the rifle barrel; with the shorter carbine barrels the .30-30 is a better choice. With the long barrel, however, the 7-30 provides flatter trajectory, and a longer effective range, as well as reduced recoil from the lighter bullets. Despite the advantages, the 7-30 still lags far behind the venerable .30-30 in popularity, however.

Where the 7-30 has gained a strong foothold is in handguns. In the field of handgun metallic silhouette shooting, a suitably loaded 7-30 Waters provides performance equal to other 7mm wildcats, such as the 7mm International Rimmed, but without the work of forming cases. It also adds the bonus of being able to shoot commercial ammunition, with some performance loss.[14] [15]

References

Notes and References

  1. Web site: C.I.P. TDCC datasheet 7-30 Waters . CIP . https://web.archive.org/web/20230430205300/https://bobp.cip-bobp.org/uploads/tdcc/tab-ii/tabiical-en-page20.pdf . 2023-04-30.
  2. Book: Cartridges of the World, 10th Ed. . Krause Publications . Frank C. Barnes, ed. Stan Skinner . 2003 . 0-87349-605-1.
  3. https://archive.today/20130630091419/http://stevespages.com/jpg/cd730waters.jpg "7-30 Waters", retrieved 2013 May 04
  4. http://www.federalpremium.com/products/rifle.aspx Federal Premium Ammunition, retrieved 2012 May 15
  5. http://www.hornady.com/store/leverevolution Hornady LEVERevolution, retrieved 2012 May 15
  6. Web site: Speer Bullets, #1625 Hot-Cor, retrieved 2012 May 15 . 2012-05-16 . https://web.archive.org/web/20111110212836/http://www.speer-bullets.com/ballistics/detail.aspx?id=47 . 2011-11-10 . dead .
  7. Web site: Hornady FTX, retrieved 2012 May 15 . 2012-05-16 . https://web.archive.org/web/20120614141717/http://www.hornady.com/store/FTX . 2012-06-14 . dead .
  8. Web site: Hornady MonoFlex, retrieved 2012 May 15 . 2012-05-16 . https://web.archive.org/web/20120430050719/http://www.hornady.com/store/MonoFlex-Bullets . 2012-04-30 . dead .
  9. Web site: Custom Shop, retrieved 2012 May 12 . 2012-05-16 . https://web.archive.org/web/20120510211656/http://www.tcarms.com/customShop/ . 2012-05-10 . dead .
  10. http://www.chuckhawks.com/sd.htm The Sectional Density of Rifle Bullets, retrieved 2012 May 18
  11. Book: Hodgdon Data Manual, 26th Ed..
  12. Web site: Nosler, Bullets, retrieved 2012 May 18 . 2012-05-19 . https://web.archive.org/web/20100629195523/http://www.nosler.com/Bullets.aspx . 2010-06-29 . dead .
  13. Web site: Hornady, .284 7mm Products, retrieved 2012 May 18 . 2012-05-19 . https://web.archive.org/web/20120430051429/http://www.hornady.com/store/.284-7mm . 2012-04-30 . dead .
  14. Web site: 7mm International Rimmed . dead . https://web.archive.org/web/20081212124349/http://www.reloadbench.com/cartridges/w7mmintrim.html . 2008-12-12 .
  15. Web site: 7-30 Waters . Accurate Arms . 2011-10-27 . 2008-11-20 . https://web.archive.org/web/20081120151720/http://www.accuratepowder.com/data/PerCaliber2Guide/Handgun/Standarddata/284Cal(7mm)/7%2030%20Waters%20T_C%20pages%2070%20and%2071.pdf . dead .