The .30-06 derived cartridges are the largest single family in American sporting ammunition. Five of them reached factory production and are still sold today: the .270 Winchester, the .25-06 Remington, the .280 Remington, the .35 Whelen and the .338-06 A-Square. Behind those sit a long line of wildcats that never got a factory headstamp, including the 6.5-06 and the .400 Whelen. One of the five outsold nearly every hunting cartridge ever made. Another has spent its whole life as a handloader’s project with a SAAMI-style name attached. This article covers all of them. For the parent cartridge itself, its military service and its own ballistics, see our full article on the .30-06 Springfield.
Why This Case Necks Up and Down So Readily
Pull the SAAMI drawings for the .30-06 Springfield, the .270 Winchester, the .25-06 Remington and the .35 Whelen and lay them on top of one another. Below the shoulder they are the same drawing. Every one of them has a rim and head .473 inch across, a body .4698 inch at the .200 datum, and a shoulder cut at 17 degrees 30 minutes. What changes is the diameter of the neck and the bullet that goes in it.
That shared geometry is the whole reason the family exists. A rifle maker building a .35 Whelen on an existing .30-06 action changes the barrel and nothing else. The bolt face already fits. The magazine box already holds a cartridge 3.34 inches long. Extractor, feed rails and receiver ring carry over untouched. For a handloader the barrier is lower still: dies, a case trimmer, and a supply of the most common brass in North America.
The case holds about 68 grains of water, enough to drive a 100-grain .257 bullet past 3,200 fps and enough to push a 250-grain .358 bullet to 2,400. That span of usable calibers, .25 through .40, is unusually wide for one case head. Only the .375 H&H Magnum has fathered a comparable number of sporting cartridges.
Two members of the family use a longer case than their parent. The .270 Winchester and the .280 Remington both run 2.540 inches, the length of the .30-03 that the Army shortened in 1906 to make the .30-06. Winchester kept the original case when it necked the design down to .277 in the 1920s. The .25-06 and the .35 Whelen use the shorter 2.494-inch .30-06 case.
The .30-06 Derived Cartridges at a Glance
| Cartridge | Bullet dia. | Case length | SAAMI MAP | Load | Muzzle vel. | Muzzle energy |
|---|---|---|---|---|---|---|
| .25-06 Remington | .257 in | 2.494 in | 63,000 psi | 100 gr | 3,230 fps | 2,317 ft-lb |
| .25-06 Remington | .257 in | 2.494 in | 63,000 psi | 120 gr | 2,990 fps | 2,383 ft-lb |
| 6.5-06 (wildcat) | .264 in | 2.494 in | none | 140 gr | 3,000 fps | 2,799 ft-lb |
| .270 Winchester | .277 in | 2.540 in | 65,000 psi | 130 gr | 3,060 fps | 2,704 ft-lb |
| .270 Winchester | .277 in | 2.540 in | 65,000 psi | 150 gr | 2,850 fps | 2,706 ft-lb |
| .280 Remington | .284 in | 2.540 in | 60,000 psi | 140 gr | 3,000 fps | 2,799 ft-lb |
| .280 Remington | .284 in | 2.540 in | 60,000 psi | 150 gr | 2,890 fps | 2,783 ft-lb |
| .30-06 Springfield | .308 in | 2.494 in | 60,000 psi | 180 gr | 2,700 fps | 2,914 ft-lb |
| .35 Whelen | .358 in | 2.494 in | 62,000 psi | 200 gr | 2,675 fps | 3,179 ft-lb |
| .35 Whelen | .358 in | 2.494 in | 62,000 psi | 250 gr | 2,400 fps | 3,198 ft-lb |
| .338-06 A-Square | .338 in | 2.494 in | not listed | 210 gr | 2,750 fps | 3,527 ft-lb |
| .400 Whelen (wildcat) | .411 in | 2.494 in | none | 300 gr | 2,300 fps | 3,525 ft-lb |
Read down the energy column and the shape of the family shows up. From .25 to .30 caliber, muzzle energy sits between roughly 2,300 and 2,900 foot-pounds, and the shooter is trading velocity against bullet weight rather than power against power. Above .30 caliber the numbers step up, because a heavy .358 or .338 bullet at sane pressure carries more energy than a light .257 bullet driven fast. The larger bores buy that with recoil and trajectory.
.270 Winchester (1925)
Winchester Repeating Arms brought out the .270 in 1925 as a chambering for its new Model 54 bolt-action rifle. The company took the 2.540-inch .30-03 case, necked it to hold a .277-inch bullet, and loaded a 130-grain spitzer at an advertised 3,160 fps. Nothing else in an American sporting rifle shot that flat in 1925.
Sales were slow at first. What turned the cartridge into an institution was Jack O’Connor, who bought a Model 54 in .270 the year it appeared and spent four decades writing about it in Outdoor Life. He took something like three dozen species with it across North America, Mexico, India and Africa, including elk, moose and grizzly, and he kept telling readers that a .270 with a good 130-grain bullet would handle nearly anything on the continent. Enough hunters believed him that the .270 became a fixture in gun racks that never held a copy of the magazine.
SAAMI rates the .270 Winchester at 65,000 psi maximum average pressure, the highest in the family and higher than the parent .30-06 at 60,000. Factory loads run from 90-grain varmint bullets to 160-grain round noses, with 130 and 150 grains carrying most of the market. Free recoil in an eight-pound rifle runs several foot-pounds below a .30-06 firing a 180-grain load, a real difference at the bench and part of why the .270 sells so well to hunters who are honest about how much recoil they enjoy.
Still in production? Emphatically. Every major ammunition maker loads it, essentially every maker of bolt-action hunting rifles chambers it, and you can buy it in a hardware store. Among cartridges built on the .30-06 case, it is the commercial giant, and it has outsold most cartridges of any lineage.
What it is for. Deer, antelope, sheep, goats and black bear at any range you have business shooting, with 130 to 140-grain bullets. Elk with a well-built 150-grain bullet inside sensible distances. It gives up bullet weight to the .30-06 and gets flatter trajectory and softer recoil in exchange.
.25-06 Remington (wildcat 1912, factory 1969)
Charles Newton necked a .30-06 case down to .25 caliber as early as 1912. A. O. Niedner was building rifles for a version he called the .25 Niedner by 1920, and Townsend Whelen worked on the same idea. All of them ran into the same wall. The powders available in the 1920s burned too fast for a case that large behind a bullet that small, which meant a wall of muzzle blast, indifferent velocity and throats that eroded quickly.
The cartridge came good when the powder did. Once slow-burning propellants in the H4831 class reached the civilian market after the Second World War, the .25-06 finally delivered what its dimensions had always promised. Remington standardized it in 1969, nearly half a century after the first rifles were built for it, and chambered the Model 700 for it.
SAAMI puts maximum average pressure at 63,000 psi. Factory loads run 90 to 120 grains, from about 3,440 fps with the lightest bullets down to 2,990 with the heaviest. The 100-grain load at an advertised 3,230 fps is the classic. Barrel life is shorter than a .270’s, which is the price of pushing a small bullet with a large charge, and most .25-06 shooters accept that as part of the deal.
Still in production? Yes, with caveats. Remington, Winchester, Federal and Hornady all load it, and several makers chamber rifles for it. Ammunition can be hard to find outside well-stocked shops, and the cartridge has a following among handloaders that outruns its shelf space.
What it is for. Open-country deer and antelope, and serious varmint and predator work at distance. With a 115 or 120-grain bullet it kills deer cleanly a long way off. It is light for elk and most people who own one know it.
.280 Remington (1957)
Remington introduced the .280 in 1957 for the Model 740 autoloader and the 760, 721 and 725 bolt guns. On paper it should have been the best cartridge in the family. A 7mm bore gives the highest sectional densities and ballistic coefficients available at any given bullet weight, on the same case that made the .270 famous.
Two decisions held it back. The first was chambering it in a gas-operated rifle: loads had to stay mild enough to keep the Model 740 running, which meant the .280 arrived showing worse numbers than the .270 Winchester it was meant to answer. The second was arithmetic. The .270 had a 32-year head start and Jack O’Connor.
The rescue attempt made things worse. In 1979 Remington raised the pressures and renamed the cartridge the 7mm Express Remington. Buyers confused it with the 7mm Remington Magnum, a genuinely dangerous confusion in a gun shop, and Remington changed the name back to .280 Remington in 1981. The SAAMI drawing still carries the line “PREVIOUSLY DESIGNATED 7MM EXPRESS REMINGTON.” A run of barrels from that period was marked 7mm-06.
One design detail deserves mention. The .280’s shoulder sits about 0.050 inch forward of the .30-06’s and the .270’s. A .270 Winchester round has a .277 bullet and a .280 rifle has a .284 bore, so a .270 cartridge chambered in a .280 by mistake would be an expensive experiment. The forward shoulder keeps a .280 round out of a .270 chamber.
Still in production? Yes, at modest volume. Remington, Federal, Winchester, Nosler and Hornady all catalog loads, typically 139 to 165 grains at 2,800 to 3,090 fps. SAAMI holds it to 60,000 psi, the same ceiling as the .30-06, and handloaders routinely get more out of it than the factory numbers suggest because the factory loads remain conservative.
What it is for. Everything the .270 does, with a slightly wider bullet selection at the heavy end. A 160 or 175-grain 7mm bullet is a better elk proposition than anything the .270 offers. Handloaders get the most from it. Buyers who want ammunition available everywhere are better served by the .270.
.35 Whelen (wildcat 1922, factory 1987)
The .35 Whelen is a .30-06 case opened up to take a .358-inch bullet, and the .30-06’s generous shoulder survives that operation with room to spare. The result is a standard-length cartridge that throws 200 to 250-grain bullets at 2,400 to 2,900 fps out of an ordinary bolt action.
Who actually designed it
The honest answer is that the two men involved gave different accounts at different times, and the record supports both readings in part.
Colonel Townsend Whelen was the commanding officer of Frankford Arsenal in the early 1920s. James V. Howe, later a partner in the custom shop Griffin & Howe, was the toolmaker. In a 1923 American Rifleman piece Whelen described the .35 as the first cartridge he designed and credited Howe with the tooling. In his 1940 book Whelen revised that, writing that Howe showed him a cartridge Howe had developed, asked permission to call it the .35 Whelen, and that Howe “alone deserves credit for its development.”
Take the 1940 account at face value and Howe designed it and named it after a friend. Take the 1923 account and it was collaborative. What is settled: the work was done around 1922, both men were involved, and Whelen commanded Frankford Arsenal. Accounts placing him at Springfield Armory have the wrong arsenal.
Sixty-five years as a wildcat
Through the 1920s the .35 Whelen was sold to American hunters as the poor man’s .375, a way to approach .375 H&H Magnum performance without a magnum action. That pitch lost most of its force in the 1930s when the .375 H&H itself became widely available in American rifles. The Whelen carried on as a wildcat, kept alive by gunsmiths and handloaders, until Remington standardized it in 1987. SAAMI issued the drawing in January 1988, the year the Model 700 Classic appeared in the chambering, a one-year run of 8,805 rifles.
Still in production? Yes. Remington loads 200 and 250-grain Core-Lokts at 2,675 and 2,400 fps. Federal, Hornady, Nosler and Barnes each offer at least one load, with the fastest factory numbers coming from Hornady’s 200-grain Superformance and Barnes’s 180-grain TTSX, both around 2,900 fps from a 24-inch barrel. SAAMI maximum average pressure is 62,000 psi. Rifle selection is thin and always has been.
What it is for. Moose, elk, big bear and heavy timber, where a wide heavy bullet at moderate velocity does more good than a narrow fast one. Inside 250 yards it is one of the more effective things you can put in a standard-length action. Past 300 the trajectory falls away quickly.
.338-06 A-Square (wildcat 1960s, standardized 1998)
Necking the .30-06 to .338 was an obvious move once the .338 Winchester Magnum arrived in 1958 and gave American shooters a reason to want .338 bullets. Wildcatters had been there earlier with the .333 OKH, which used .333-inch British bullets; the .338-06 made that design redundant by using components anyone could buy.
A-Square, the semi-custom rifle and ammunition house founded by Lieutenant Colonel Arthur B. Alphin in 1979, adopted the cartridge, put its name on it and submitted it for standardization around 1998. Weatherby chambered rifles for it from about 2001 and sold a single load, a 210-grain Nosler Partition at an advertised 2,750 fps. The rifles are gone from Weatherby’s catalog. A-Square itself ceased to exist in February 2012. Nosler has offered small runs of custom ammunition since.
Ballistically the case is sound. A 200-grain bullet at 2,773 fps makes 3,416 foot-pounds and a 250-grain at 2,531 makes 3,557, which is .35 Whelen power with better ballistic coefficients and rather less recoil than a .338 Winchester Magnum. The .338-06 A-Square does not appear in SAAMI’s current centerfire rifle standard.
Still in production? Barely. Factory rifles are gone and factory ammunition is a special-order item at premium prices. Anyone buying one today is buying a handloading project and should line up dies, brass and bullets before the rifle.
What it is for. Elk, moose and large bear for a shooter who handloads and wants .338 bullets in a standard action. It is a genuinely good cartridge with a small following, and it is the clearest example in this family of a sound design that the market declined.
The Wildcats That Stayed Wildcats
6.5-06
The .30-06 necked to .264 has been built by gunsmiths for most of a century. It is close enough to the .256 Newton, a commercial cartridge from the 1910s, that the idea can hardly be called new. A-Square standardized a version with SAAMI in 1997 as the 6.5-06 A-Square and listed two rifles for it, the Hamilcar and the Genghis Khan.
No major ammunition maker has ever loaded it. A-Square closed in 2012 and the chambering does not appear in SAAMI’s current centerfire rifle standard. Handloaders get about 3,000 fps from a 140-grain bullet and 3,400 from a 100-grain, which puts it a step ahead of the 6.5 Creedmoor and roughly level with the 6.5 PRC. The Creedmoor took the market the 6.5-06 might have had, on the strength of factory ammunition, short-action rifles and a decade of competition results.
.400 Whelen
Whelen and Howe built this one in 1922 alongside the .35, opening the .30-06 case up to take the .411-inch bullets made for the .405 Winchester. Griffin & Howe chambered custom rifles for it. With a 300-grain bullet at about 2,300 fps it makes roughly 3,500 foot-pounds, which is a great deal of cartridge for a standard-length action.
The trouble is geometry. Open a 17-degree-30-minute shoulder out to .40 caliber and almost nothing is left of it for the case to headspace on. The cartridge earned a bad reputation for exactly that, with reports of a firing pin strike shoving the case forward in the chamber before the primer went off. Defenders of the design point out that Whelen’s original drawings kept more shoulder than the later copies did, and that rifles built to his specification behaved themselves. Either way the .400 Whelen never reached factory production, and it survives as a wildcat for people who fire-form their own brass to one chamber.
.375 Whelen and the improved cases
The .375 Whelen, sometimes written .375-06, sits between the .35 and the .400 and gives a handloader the large stock of .375-inch bullets on cheap .30-06 brass. It loses some shoulder in the process, though less than the .400 does.
A second line of wildcats keeps the .30-06 bore and reworks the case instead. P. O. Ackley’s Improved versions blow the shoulder out to a sharper angle and reduce body taper to gain capacity; Rocky Gibbs, working in Idaho in the 1950s, moved the shoulder well forward. Both produce a case that must be fire-formed from standard brass and fed only to the rifle it was formed in.
Cartridges Often Mistaken for Family Members
Two rounds get pulled into this family by mistake often enough to be worth clearing up.
The .30-03 is the parent, not the child. The Ordnance Department adopted it in 1903 with a 2.540-inch case and a 220-grain round-nose bullet. Three years later Springfield Armory shortened the case to 2.494 inches and loaded a pointed bullet, and that is the .30-06. Every account that describes the .30-03 as a .30-06 derivative has the sequence backwards. Its main legacy in the sporting world is the 2.540-inch case length that the .270 Winchester and the .280 Remington still use.
The .30 Newton is a separate design. Charles Newton’s 1913 cartridge is built on the German 11.2×72 Schuler case, with a head .523 inch across against the .30-06’s .473. It will not fit a .30-06 bolt face and it shares no dimensions with the Springfield case. Newton did work with the .30-06 case, and the .25-caliber version he made in 1912 is a genuine ancestor of the .25-06, but the cartridge carrying his name is not part of this family.
Which Ones Worked
The family divides cleanly by commercial outcome.
- .270 Winchester. A hundred years old and still one of the best-selling hunting cartridges in America. Buy one anywhere, feed it anywhere, hand it to your grandchildren.
- .25-06 Remington. A durable niche. Loaded by all four major American ammunition makers, chambered by several rifle makers, and carried mostly by people who chose it deliberately.
- .280 Remington. Technically the equal of the .270 and commercially far behind it, held there by a cautious launch, a confusing rename and the .270’s head start. Still cataloged, still worth owning if you handload.
- .35 Whelen. A small, loyal market that has survived since 1922. Factory ammunition from five makers, factory rifles in short supply, and a following among hunters who want big-bore performance in a rifle they already own.
- .338-06 A-Square. A niche inside a niche. Excellent ballistics, no factory rifles, and ammunition that is a special order. A handloader’s cartridge with a factory name.
- 6.5-06, .375 Whelen, .400 Whelen. Wildcats then, wildcats now. Sound ideas that never found a manufacturer willing to carry them, in a market that had adequate answers already.
Timing and distribution explain those outcomes better than ballistics do. The .280 beats the .270 on paper and loses on the shelf. The 6.5-06 beats the 6.5 Creedmoor on velocity and lost the market entirely. What sells a cartridge is factory ammunition in ordinary shops, rifles from ordinary makers, and someone credible telling hunters it works. The .270 got all three. The rest got some fraction, and their sales reflect exactly which fraction.
For the cartridge that started all of it, including its military service, its ball loadings and how it performs in a hunting rifle today, read our full article on the .30-06 Springfield.
References
- ANSI/SAAMI Z299.4-2025, Voluntary Industry Performance Standards for Pressure and Velocity of Centerfire Rifle Ammunition (case and chamber drawings, case lengths, head and shoulder dimensions, maximum average pressures, the 7mm Express Remington designation note, and the absence of the two A-Square chamberings from the current standard).
- .270 Winchester, Wikipedia (1925 introduction, Model 54, .30-03 parent case, factory ballistics).
- “.270 Winchester”, Ballistic Studies (original 3,160 fps advertised load, Jack O’Connor’s role, current factory data).
- .25-06 Remington, Wikipedia, and “.25-06 Remington”, Ballistic Studies (Newton 1912, Niedner 1920, the powder problem, 1969 standardization, factory loads).
- .280 Remington, Wikipedia, and “.280 Remington”, Ballistic Studies (1957 introduction and rifles, the Model 740 loading constraint, the 7mm Express rename and reversion, current factory loads).
- .35 Whelen, Wikipedia (the 1923 American Rifleman and 1940 book accounts of the attribution, Frankford Arsenal, 1922 development).
- “.35 Whelen”, Ballistic Studies (current factory loads from Remington, Federal, Hornady, Nosler and Barnes; the “poor man’s .375” marketing and the effect of the .375 H&H).
- .338-06, Wikipedia, and “.338-06 A-Square”, Ballistic Studies (wildcat origins and the .333 OKH, A-Square and Arthur Alphin, the Weatherby rifle and 210-grain load, current availability).
- 6.5-06 A-Square and .30-06 Springfield wildcat cartridges, Wikipedia (1997 SAAMI submission, the A-Square rifles, the .256 Newton precedent, the .375 Whelen, Ackley and Gibbs improved cases).
- .400 Whelen, Wikipedia (1922 development by Whelen and Howe, .405 Winchester bullets, the headspace argument, Griffin & Howe rifles, published ballistics).
- .30 Newton, Wikipedia (the 11.2×72 Schuler parent case and the .523-inch head diameter).
- “Cartridge Legacies: The .30-06 Springfield Family Tree”, American Hunter (the family roster and the comparison with the .375 H&H as a parent case).
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