6.5 – Wholesale Hunter

THE SHORT, FAT CARTRIDGE

Creating a new cartridge is complex and expensive; it is simpler and cheaper to modify existing cases. Performance characteristics can be changed by necking the case up or down, changing shoulder angle and body taper, and by shortening or lengthening the case. Such modifications create “families” of cartridges based on a parent case.

Craig Boddington

This awesome group was fired from a .300 WSM when the cartridge was first introduced. Short, fat case design is conducive to accuracy, but good barrels and consistent ammo is more important. The short, fat concept is really more about efficiency

Peter Paul Mauser created an extensive family of cartridges based on his 1888 7.92x57mm cartridge. Our .30-06 has a longer case, but rim and base diameter are suspiciously similar to Mauser’s case. (Actually, our 1903 Springfield action was so similar to the Mauser that Uncle Sam paid Mauser a royalty until WWI.) To this day, the majority of unbelted rimless cartridges are based on the .30-06’s .473-inch rim and base diameter. These include .270, .35 Whelen, and Hornady’s 6.5mm (and 6mm) Creedmoor.

Since its introduction in 1912, the .375 H&H Magnum case, with .532-inch rim and belt, has served as the parent for almost all belted cartridges. The only exceptions have been Weatherby’s smallest cartridges (.224 and .240 Wby Mag); and their largest cartridges, based on the big .378 Wby Mag with .582-inch rim and belt.

Proving that short and fat isn’t everything and extreme velocity can produce accuracy, this group was fired with a Lazzeroni 7.82 (.308) Warbird, 4000 fps with a 130-grain Barnes X bullet.

Earlier cartridges tended to have a lot of body taper and gently sloping shoulders. With new smokeless powder pressures, both features were thought essential for smoother feeding and reliable extraction. One of the most archaic of all case designs still around is the .300 H&H. Introduced in 1925 by necking down the .375 H&H case, the .300 uses the full 2.850-inch case, lots of body taper, and a long, gentle 8.5-degree shoulder. From today’s perspective, we reckon there’s no way it will shoot well or fast. Except it does both. The .300 H&H became popular when Ben Comfort used it to win the 1000-yard Wimbledon match in 1935. With good handloads, velocity is surprising, and that long, tapered case literally flies into the chamber.

Boddington took this javelina in 2002 with a .243 WSSM, when the WSSM cartridges were introduced. Fast and efficient, they do what they’re supposed to do, but didn’t become popular and have nearly vanished…perhaps because of feeding issues in many platforms.

By this time, gun tinkerers had discovered that powder capacity and efficiency could be enhanced by removing body taper and sharpening shoulder angle…with little impact on feeding and extraction. The resulting non-standard cartridges were called “wildcats.” P.O Ackley (1903-1989) was one of the most prolific experimenters. He messed with every known case and bullet diameter but, rather than reinvent the wheel, his cartridges were mostly “improved” by removing body taper and sharpening shoulder angle, thus increasing velocity.

Ackley’s rule for an “improved” cartridge: Standard factory ammo could still be used, the result a fire-formed case. The .280 Ackley Improved has been his most popular, now loaded by several companies. Based on the .280 Remington with sharp 40-degree shoulder, the .280 AI duplicates 7mm Rem Mag performance, but in a more compact case while burning less powder.

In the 1990s John Lazzeroni got the majors thinking with his fat-cased Lazzeroni Magnums. His long cartridges are perhaps best-known, but it was his short, fat cartridges that got things going. Left to right: 7.21 (.284) Spitfire; 7.82 (.308) Patriot; 10.57 (.416 Maverick).

Roy E. Weatherby (1910-1988) also started as a wildcatter. Weatherby’s initial cartridges were based on the .300 or .375 H&H case, necked this way and that, sometimes shortened, always with body taper removed to increase powder capacity and velocity. His flagship cartridge, the .300 Wby Mag, wasn’t the first but, since it used the full-length case, it was essentially just one of various “improved” versions of the .300 H&H. The Weatherby difference is Roy’s distinctively curved “double Venturi” shoulder. The effect of this is still debated but, for sure, the Weatherby Magnums were, by bullet diameter, the fastest cartridges out there.

Boddington and noted Ruger collector Lee Newton with a fine Kansas whitetail, taken with Ruger No. One in .280 Ackley Improved. The most popular of P.O. Ackley’s many cartridge designs, his .280 AI has become extremely popular.

In fact, the only the way to get higher velocities is to use a bigger case. Problem is, you quickly get into over bore capacity. This can be likened to a water hose. A hose can only pass so much water. You can increase pressure, but at some point you reach diminishing returns and not much more water comes out of the hose. In a rifle barrel, that point of diminishing return is over bore capacity. You can use a bigger case and burn more propellant, but you can’t get much more velocity. You’ll start to see this with unburned granules of powder spewed in front of the muzzle, but the real problem is throat erosion and reduced barrel life.

So long as we use nitrocellulose-based propellants, we can’t get much faster than Weatherby’s 1940s velocities. Nitrocellulose expands (burns) at about 5000 fps. This sets a practical limit, but you can’t get there because of friction. The .220 Swift broke 4000 fps in 1935. To this day, only a handful of commercial cartridges exceed 4000 fps, none by much, and all with short barrel life.

So, no matter how much superheated gas you pour down your barrel, unprecedented velocity is not the result. You can, instead, go for efficiency, and that’s a primary concept behind today’s short, fat cartridges. We learned from tank cannons that burning efficiency is achieved when the primer flame can access a greater percentage of the propellant charge. Burning efficiency is conducive to accuracy. More important: More energy per grain of powder burned. For instance, with a 180-grain bullet, the .300 Wby Mag needs 70.9 grains of IMR4350 powder to reach 2900 fps. The .300 WSM needs just 62.1 grains of the same powder. That’s ten percent more propellant—more heat, more recoil—to reach the same result.

The .308 Win is based on the .30-06 case shortened from 2.494 inches to 2.015 inches. At some point case capacity tells; the .308 is not as fast as the .30-06. However, it’s only about seven percent slower…while burning 20 percent less propellant.

For sheer efficiency, the perfect cartridge case is as wide at the base as it is long. No such cartridge exists because no known action can feed such a thing. However, there are fatter cartridge cases. A longtime favorite has been the .404 Jeffery case, an unbelted rimless cartridge with a .543-inch rim and base. The .416 Rigby case is even fatter, with a .590 rim and base.

Hornady’s growing PRC family, all based on the .375 Ruger case. Left, the just-released 7mm PRC, case shortened to house the longest bullets in standard actions. Center, the original 6.5 PRC, suitable for short actions. Right, the .300 PRC, possibly suitable for standard actions, but requiring a full-length action for the longest .308 bullets currently in use.

In the late Eighties Tucson wildcatter John Lazzeroni started developing fat-cased wildcat cartridges, creating parallel lines of long and short-cased Lazzeroni Magnums. Most use similar dimensions to the .416 Rigby, but some use the .404 Jeffery. As Roy Weatherby did in the 1940s, Lazzeroni made the big boys nervous.

Manufacturers liked the concept and the performance, but most production bolt-actions cannot house the big Rigby case. So, the big boys did their own things. Remington struck first with the long Remington Ultra Mags, based on the .404 Jeffery case. First the .300 RUM in 1998, then 7mm, .338, and .375 RUM two years later. Good and fast cartridges, all needing .375 H&H-length actions. Winchester struck back with the .300 Winchester Short Magnum, 2.1-inch case for short actions. The RUMs have a .550 base, with the rim slightly rebated to .534. Winchester’s WSM case is similar, but not the same: .555-inch base, rim rebated .535.

Remington quickly added 7mm and .300 Remington Short Action Ultra Mags, sized to fit their little Model Seven action. Soon we had four RUMs, two RSAUMs, and four WSMs…plus three Winchester Super Short Magnums (WSSMs). To my thinking, this was a large and confusing array of new cartridges. The .300 WSM has become the most popular, but several of these cartridges are languishing and the WSSMs vanished quickly. The short, fat cartridges are efficient, but remember my comment about actions for the ideal “triangular” cartridge? All the short, fat cartridges show feeding issues in some platforms, and I believe this is what killed the WSSMs, too short and fat for many actions.

: This huge feral hog was taken with a Lazzeroni 10.59 (.416) Maverick. Maybe too much gun, but the proprietary Lazzeroni short magnums are still the fastest in their class.

In 2007 Hornady introduced the .375 Ruger. It was successful, but its case design is brilliant: .532-inch rim and base, same as the rim and belt of the .375 H&H but, absent belt, more case capacity. Also, easy to manufacture: Same bolt face as a belted magnum, and untroubled feeding in most actions.

The .375 Ruger case quickly spawned the .416 Ruger and, shortened, .300 and .338 Ruger Compact Magnums (RCMs). These have not been especially popular, but recently, the .375 Ruger case was used for Hornady’s PRC (Precision Rifle Cartridges). Specified for faster-twist barrels and intended for use with modern extra-heavy, extra-long, super-aerodynamic bullets, there are now three PRCs: 6.5, .300, and the just-released 7mm PRC.

The three PRCs are designed for maximum efficiency and to avoid over bore capacity. Interestingly, case lengths are different. 6.5 PRC is a short-action cartridge. .300 PRC uses the full (2.5-inch) .375 Ruger case. With the longest and heaviest bullets, it really needs a full-length action. The 7mm PRC splits the difference with a 2.280-inch case, allowing it to be housed in standard (.30-06) actions with extra-heavy 180-grain 7mm bullets.

Nosler cartridges: The Nosler family of cartridges, now 26, 27, 28, 33, and 35 Nosler, are all based on the RUM/.404 Jeffery case. The 26 (6.5mm) Nosler was first. So far, the 28 (7mm) Nosler has been most popular, now loaded by multiple major manufacturers.

The PRCs aren’t alone in being specific to actions lengths and bullets. Starting in 2012 with the 26 Nosler, Nosler’s family has now grown to five siblings: 26, 27, 28, 30, and 35 Nosler, all based on the RUM (.404 Jeffery) case shortened to 2.5 inches. all intended as standard-length-action cartridges. Most popular so far has been the 28 Nosler, calling for faster rifling twist, and now loaded by multiple manufacturers,

Winchester’s 6.8 Western takes a different approach. Based on the .270 WSM case shortened, it is designed for short actions, so is sort of an extension of the WSM family. Except: It calls for fast-twist barrels, and is designed for the new, extra-heavy .277 bullets up to 175 grains.

In 2022, the somewhat fatter (and sometimes short) case is still in vogue, but current cartridge design is more specific to actions, bullets, and rifling twists than ever before.

USE ENOUGH GUN…For All Game

The phrase was made famous by author Robert Ruark (1915-1965). Actually, his memory, because Use Enough Gun is a posthumous collection. Naturally, we assume the admonition applies to large and dangerous game.

Craig Boddington

The phrase was made famous by author Robert Ruark (1915-1965). Actually, his memory, because Use Enough Gun is a posthumous collection. Naturally, we assume the admonition applies to large and dangerous game. So, let’s be clear: This story is not about animals that might gore, trample, bite, or eat you.

The greater kudu is a large African antelope, not as big as fully mature elk, but similar in size to a three-year-old five-point bull. Like elk, shots can come at any range. “Enough gun” at 200 yards is one thing, and quite another at twice that distance.

I’ve written those articles (and entire books), but that’s a simple subject. Most African jurisdictions have game laws that tell us what constitutes “enough gun.” In some countries, these are broad, such as “minimum .375 for all dangerous game.” Other areas have more specific rules, sometimes including minimum energy standards. Rather than guidelines, these are enforceable statutes. We can disagree and exceed the standards, but if our chosen rifles and cartridges don’t meet the minimums, we’re breaking the law.

Most US states that allow rifle hunting have a minimum legal caliber. Today, thanks to the widespread popularity of the AR platform, most jurisdictions now allow .223s, at least for deer. Some elk states maintain a higher standard but in most areas, we can now legally hunt deer and wild hogs with .22 centerfires.

“Enough gun” for dangerous game is subject to much debate but is simplified by minimum standards in most African jurisdictions. Widespread belief is the .375 H&H is the usual legal minimum, but it’s more commonly the European equivalent 9.3mm (.366-inch), with either the 9.3x74R or 9.3×62 Mauser usually legal.

On mature bucks and big boars, I’m not convinced this is a great idea, but many of us do it (me included). Light recoil and accuracy make shot placement easy. For brain and neck-shot specialists, the .223 is plenty of gun, and it doesn’t much matter what bullet is chosen. Folks like me, who prefer body shots, are better served by tough, heavy-for-caliber bullets designed for larger game.

Still may not be the best choice. Entrance holes are tiny and exits are unlikely. On larger deer, definitely on hogs, my experience is recovering game shot with .22 centerfires requires more tracking…and there isn’t much trail to follow.

This Texas hog was taken with a brain shot from a little .22 Hornet. Definitely not enough gun, but careful close-range hunters who specialize in brain shots can be a bit more flexible in cartridge choices.

Whether you’re one of the guys who “only does brain shots,” or, like most of us, you usually take the biggest, surest chest shot, when hunting big game with .22 centerfires the bottom line is the same. You must get close. In the first instance, because the head shot is a tricky target; 100 yards is a long brain shot. In body shots with .22 centerfires, you don’t have much bullet energy anyway, and you need all you have. Faster cartridges like the .22-250 offer more range, but when I hunt deer with a .223 I figure about the same 100-yard maximum.

Now, it’s impossible to quantify exactly how much gun is “enough.” No two shots are exactly alike, with nuances of angles, distances, shot placement, and bullet performance. There are no absolutes. Ideal shot placement—with a bit of luck—may mask inadequacy…until it doesn’t. And the reverse: Make a bad shot, and one’s natural impulse is to blame the cartridge or bullet. There’s no precise formula, but our vast array of cartridges offers plenty of good choices.

Boddington and Zack Aultman with a Georgia hog, rolled with a body shot from a .22 centerfire AR. Although many use .223s for hogs, this is a bit of a false reading: .22 centerfires aren’t enough gun for body shots on big hogs…and this isn’t a very big hog!

Recognizing “enough gun” for dangerous game may be the easiest of all. Nobody takes long shots at big bears or buffaloes, so there’s little concern about trajectory or residual energy. What you start with better be enough. Everything else is more difficult, especially with today’s fascination with shooting at longer ranges. We really need to think about two criteria: Enough velocity, energy, and bullet weight for the close shot we might get; and enough for the long shot we might want to take. These are not exactly the same.

In North America, elk is a major animal that sparks the “enough gun” debate. Boddington used a .270 to take this New Mexico bull, very cleanly with one shot. The .270 is the lightest cartridge he has used for elk, but believes the faster 6.5mms are enough gun…but not at longer ranges.

I like the 6.5 Creedmoor, but I don’t credit it with magical powers. Its 140-grain bullet is not heavy, and its 2700 fps velocity is not fast. Past 300 yards it starts to drop quickly…as does residual energy. A young writer friend who did credit the Creedmoor with magical properties was convinced it’s a 400-yard elk cartridge. At that distance, his elk was wounded and lost. Sometimes we get away with folly, sometimes we don’t, but the Creedmoor is well below the line for elk-sized game at longer ranges.

Boddington used his .264 Winchester Magnum to take this excellent Wyoming mule deer. Ballistically identical to the 6.5 PRC, faster 6.5mms are ideal for deer-sized game at any sensible range, but perhaps a sound minimum for elk-sized game, and not at extreme range

Ringing steel with the Creedmoor at 1000 yards is easy and fun, but that isn’t the same as shooting at game. The steel target doesn’t care how hard or soft the strike; it’s going to ring. My longest shot on game with a Creedmoor was a whitetail at 325 yards. On deer-sized game, the Creedmoor has power and performance beyond that, but you must do things right. We mis-ranged the buck, adjusting for 300 yards vice 325. Doesn’t sound like much, but I needed two more clicks up and hit the buck low. The rangefinder probably caught an unseen branch, not uncommon. I corrected, held higher and hit him again. A flatter-shooting cartridge would have eliminated an almost-miss.

With perfectly steady position, John Stucker is about to shoot a zebra at 400 yards with his Christensen 6.5 PRC with 143-grain ELD-X.

I like the awesome downrange performance of the 6.5mm’s long, aerodynamic bullets, so I’m becoming a fan of the 6.5 PRC. With 140-grain bullet at 3000 fps, it is 300 fps faster than the Creedmoor, delivering more energy and shooting much flatter. There’s no magic in this formula; the old .264 Winchester Magnum does the same, as do the 6.5/.284 Norma and the new 6.5 Weatherby RPM. I have a good .264, but the 6.5 PRC, with modern case design, is better-suited for today’s longer, heavier “low drag” bullets. Although I’m new to the 6.5 PRC, I’ve taken a lot of game with the .264: Deer, sheep, goats, African plains game. I thought I had a pretty good idea of the size of game this level of 6.5mm was “enough gun” to handle. For sure, I considered it elk-adequate to considerable distance, if not extreme range.

B oddington and John Stucker with Stucker’s Burchell’s zebra, taken at 400 yards with a 6.5 PRC. Maybe it would have worked perfectly if the first shot had been two inches left…and maybe not. Collective summation: Not quite enough gun for large, tough animals at that distance

My buddy John Stucker has a Christensen Ridgeline in .300 Winchester Magnum, accurate, powerful, a wonderfully versatile rifle. Last year in Georgia, John used a borrowed 6.5 PRC and flattened a big-bodied buck in its tracks. He liked the cartridge so much that he bought another near-identical Christensen in 6.5 PRC.

This year we had a South African plains game hunt planned with Carl van Zyl’s John X Safaris. Stucker had an obvious choice in his Christensen .300. However, he was focused on smaller antelopes often taken at longer ranges: Vaal rhebok, klipspringer, steenbok, mountain reedbuck, nothing “big” on his wish list. He decided to take his 6.5 PRC and, for sure, I agreed 100 percent.

Boddington’s son-in-law, Brad Jannenga with a nice axis deer (similar in size to mule deer), taken with an old .300 Savage lever-action. For deer-sized game there are dozens of adequate cartridges. On larger game, more thought should be given to cartridge adequacy

Africa’s pygmy antelopes often mean difficult shooting. Obviously, the 6.5 PRC was plenty of gun, and Stucker was on a roll. With great shooting and good luck, he was done early, so he added zebra and maybe a kudu to his list. An average kudu bull is much the same size as maybe a youngish five-point or raghorn elk. At possibly 800 pounds, a zebra is as big, and as tough, as a big bull elk. John’s .300 would have been perfect, but we had no reason to question his 6.5. His PH, “Stix” Hoole, an astute “gun guy,” was also in agreement. Should be fine.

Left to right: 6.5×55 Mauser, 6.5 Creedmoor, .260 Remington. These 6.5mms are almost identical in ballistics: 140-grain bullet at about 2700 fps. They are awesome for deer-sized game, but adequate for elk only at closer ranges…with excellent shot placement.

Here’s where nuances of shot placement, distance, and luck come into play. John got a shot at an older, big-bodied kudu bull with terrible horns, a “management” bull. One 143-grain ELD-X crumpled the bull, perfect shoulder shot at 380 yards. We were all stoked and gratified; the 6.5 PRC was obviously plenty of gun.

Unfortunately, the zebra told a different story. John’s first shot was just over 400 yards. The way folks tell it these days, that’s not far, right? From a steady position with data well dialed-in, very do-able. However, from muzzle energy of 2782 ft-lbs, residual energy at 400 yards was 1800. Again, nuances. Maybe the animal was quartering a few degrees, or maybe the first shot was a couple inches too far forward. Whatever. The first shot on the shoulder didn’t do the job. Nor did additional shots, apparently perfectly placed despite increasing distance. The animal went down, but when we approached it jumped up and needed a close-range finishing shot.

Faster 6.5mms flatten trajectories and deliver more downrange energy. These 6.5mms all deliver 140-grain bullets at about 3000 fps, left to right: .264 Winchester Magnum, 6.5-.284 Norma, 6.5 PRC, 6.5 Weatherby RPM. All are fully adequate for elk, but their relatively light bullets suggest caution at longer ranges

I can’t tell you how many more feet per second in velocity, how many more foot-pounds of energy, or how many more grains of bullet weight we should have had for that zebra. Nor, precisely, can anyone else. I don’t even know for absolute certainty that we didn’t have enough. Maybe if the first shot had been two inches farther left we’d still be congratulating each other on a great shot, made with a perfect choice of cartridge and bullet. But I don’t think so, because the lesson isn’t new. The last time I used my .264 in Africa (140-grain bullet at 3000 fps, so ballistically the same as Stucker’s 6.5 PRC), I remember thinking that larger, tougher antelopes—and zebra—traveled a bit farther with well-placed hits than would have been the case with 7mm or .30-calibers with heavier bullets. The problem with using “enough gun” is that nobody can say exactly what that is for various sizes and types of game. It only becomes obvious when you don’t have quite enough!