Marvellous medium bores

David Duffy takes aim with some of the more popular calibres

It could be a fleeing once-in-a-lifetime 30″ sambar stag that doesn’t present a perfect broadside shot, crashing through the undergrowth. You may be in the Outback after a big bull camel, but the closest you can make is 320 paces from him. Or perhaps you’re in Arnhem Land and there’s a mean-looking buffalo watching and you’re just not sure whether he’s taken a dislike to you. In these situations, a rifle chambered in a medium bore cartridge might be the ideal remedy.

The medium bores start at .33 calibre and go to .375. There are some fine cartridges suitable for large game in 8mm (.323) but traditionally 8mm wasn’t classed as a medium bore. The medium rounds can have a few advantages over big bore cartridges, such as manageable recoil and often come in a rifle that isn’t as heavy.

It is far better to have a cartridge that you can shoot accurately under stress than a bigger more powerful cartridge that you can’t. Nevertheless, on heavy dangerous game such as Cape buffaloes, the big bores are better stoppers than the medium bores, provided you can shoot them accurately and have them back on target quickly if you need a follow-up.

If I were to nominate the king of the medium bores, it would be the .375 H&H. But here is a run-down of some of the more popular options.


Firearms author Elmer Keith was a strong advocate of the .33 calibre, .333 at first and then .338 when projectiles in that diameter became readily available. Elmer shot 50 bull elks in his lifetime and guided many hunters on elk excursions.

He helped develop the .333 OKH and later the .338 OKH, both of which used the .30-06 case necked up to accept .33 bullets. Elmer maintained that you needed at least 250gr projectiles of .33 calibre to consistently take elks, mule deer, bears, moose and the larger African plains game. When he compared .338 calibre to .358 and .375, he considered .338 to have an advantage on the longer shots due to better sectional density of similar weight projectiles, while not giving away much on the closer shots due to excellent penetration.

Nowadays, there are a wide variety of .338 projectiles that have high ballistic coefficients (BC). Up until recently, .338 calibre was the only serious medium bore for long-range shooting either at targets or game for those inclined.

For close to moderate distances, the .338-06 is a top choice for large game such as sambar. Recoil is reasonable and this cartridge can be packaged in a rifle with a relatively light configuration, due to recoil being less than say the .338 Win Mag.

I think the .338 RCM is even better than the .338-06, because it fits in a short action, holds one-two grains more of powder and the shorter, fatter powder column burns efficiently. All this translates to a cartridge that can be housed in a rifle with a short action, 20″ barrel and a lighter weight than a .338-06 with a long action and 24″ barrel but giving the same velocity figures.

With a little modification of the floorplate, my Ruger Hawkeye holds four .338 RCM rounds in the magazine and I obtain 2720fps out of the 20″ barrel using Reloder 17 with the 225gr Woodleigh PPSN. The .338 Federal also fits in a short action, but case capacity is much less, so using heavy .338 projectiles is not practical. It shines with 180-200gr projectiles.

The most popular .338 for hunting is the .338 Win Mag. In my Winchester Model 70 the magazine is long enough to seat the projectiles way out to 3.52″. With the chamber long-throated, I gain 2950fps out of the 25″ barrel using AR2209 with the 225gr TSX and TTSX. This makes the .338 WM suitable for long shots on big game. The 300gr Woodleigh would be my choice in the .338 WM for water buffaloes/bantengs/scrub bulls. My rifle weighs 4.2kg with scope, which isn’t light but makes the firearm reasonable to shoot. An advantage with the .338 WM over bigger cases is that I can fit four rounds in the magazine by having a slight modification to the magazine wall.

Other good hunting cartridges I like in .338 include the .338-375 Ruger with the shoulder moved back to give a reasonable neck length and the .330 Dakota which uses the slightly wider .404 Jeffrey parent case. These cases don’t have a belt, don’t have a rebated rim (such as the 33 Nosler) and are a similar length to the .338 Win Mag case. Velocities are around those of the longer .340 Weatherby which is a good round. The .338 Ultra Magnum is fast, but you really need an even heavier rifle to absorb the extra recoil.

For long-range shooting or hunting, I was impressed with a rifle chambered in .338 Lapua Improved I used in Oregon. The rifle weighed just more than 9kg and had a muzzle brake inside a titanium suppressor. Recoil, muzzle blast and noise were significantly reduced making it easy to shoot well.


The .35 Whelen is the most popular .35 and it uses the .30-06 case necked up to .358. The .35 Whelen is an excellent woods cartridge. At close distance the slightly bigger diameter projectile over the .338-06 gives a marginal advantage, but it loses out to the .338-06 over longer range. The 250gr projectiles are a fine choice in this round.

A good wildcat is the .35 Sambar which is the WSM case necked up to .358. Velocities are arbout 2800fps out of a 22″ barrel with 225gr projectiles. This cartridge, as its name suggests, was developed for sambar hunting and uses a short action and usually a 20-22″ barrel to give a light portable rifle.

Using the WSM case gives a few grains more powder than using the RCM. However, I prefer the RCM because it feeds better due to it being slightly narrower and having a 30-degree shoulder. The RCM doesn’t have a rebated rim which is another advantage, plus in some rifles such as my Ruger Hawkeye, the magazine can be modified to hold four RCM rounds but you can’t fit in four WSM rounds. The .358 Winchester uses a necked-up .308 case. Elmer Keith thought that with a 250gr projectile it is better than any .30 calibre at close range and he recommended it for ladies as a woods choice.

The .358 Norma Magnum is not too popular nowadays, but gives excellent performance (.358 equivalent of the .338 Win Mag) as does the more powerful .358 Shooting Times Alaskan which uses the longer 8mm Remington case with less body taper and 35-degree shoulder.

Woodleigh make a 275gr projectile which would give deep penetration on tough game using these two cartridges. The ballistic coefficients of .35 calibre projectiles isn’t as good as the .338 projectiles, but this doesn’t matter at close range.


The 9.3×62 case is similar to the .30-06 (necked up) but they have dimensional differences, especially around the head, so making cases out of .30-06 brass is not advisable. The shoulder is moved further forward on the 9.3, giving a slight powder capacity increase at the expense of a shorter neck.

The bullet diameter of .366″ is only slightly bigger than .358 yet the 9.3 has a better selection of heavy bullets with 286gr being common. There are some European rifles chambered in 9.3×62 and factory-loaded ammunition is available. The cartridge can be used in some African countries for hunting dangerous game, whereas the .358 calibre usually can’t.

Performance of the 9.3×62 on large game is excellent and it doesn’t recoil as much as the .375 H&H while magazine capacity is greater.

The 9.3x74R is a rimmed case (with similar performance as the 9.3×62) that is often used in double rifles. The 9.3×62 is increasing in popularity and is also a good choice for sambar, camels at moderate distances and can be adequate for water buffaloes/bantengs/scrub bulls, though I would prefer a bigger case such as the 9.3×64 Brenneke for these last three.

The 9.3×64 case is only marginally wider than the 62 case, which means that in many rifles, you can have four rounds in the magazine. The 9.3×64 holds roughly 10 grains more water than the 9.3×62 and should be far more popular than it is. A Mauser 98 Sporter chambered in 9.3×64 would be close to perfection and RWS make top-quality brass.


As good as the 9.3×64 Brenneke is, it is still not legal for dangerous game in some African countries, with .375 being minimum. The .376 Steyr is the 9.3×64 case necked-up to .375 but disappointingly shortened to 60mm, it didn’t become popular.

Holland & Holland brought out the .375 H&H in 1912 and the cartridge has an enviable reputation in Africa as ideal for a client wanting to use one gun on plains game and dangerous game. Renowned outdoorsman Jack O’Connor liked the .375 H&H on lions. A client hunting heavy, threatening game such as Cape buffaloes with a .375 H&H will have a professional hunter often with a big bore double rifle to back him up if things go wrong.

Fabled hunter Warren Page, who popularised the 6mms, preferred the slightly more powerful .375 Weatherby but the .378 Weatherby based on the much bigger case has too much recoil. The .375 H&H has about the most recoil that the average hunter in the Top End of Australia or going to Africa can tolerate.

Many of those who shoot ultra-long distances consider that the .375 CheyTac which uses a modified .505 Gibbs case necked down to .375, together with the latest high BC projectiles in .375 weighing 350gr or more, outperforms the .338 Lapua when shooting distances of around 2380m or greater. A bigger action and heavier rifle are needed to deal with the size of the cartridge and extra recoil, and some components are more expensive.

If correctly head-stamped brass is not an issue and you wish to rebarrel a .338 WM or .458 WM to .375, the .375-338 Win Mag (.375 Chatfield-Taylor) gives similar performance as the .375 H&H, but in a standard-size (.30-06 length) action. Little or no modification of the feed rails, magazine or follower is needed and you can neck up or down your .338/.458 brass.

The standard-length beltless .375 Ruger has the same diameter as the belt on the longer .375 H&H. The .375 Ruger can fit in a more compact, lighter rifle and is chambered in blued and stainless models. For the big bears, elks and moose in North America the .375 Ruger is probably a better choice than the .375 H&H, partly because of the rifles it is chambered in.

My preference would be the Hawkeye FTW Hunter with a modified floorplate to hold four rounds in the magazine, and not use the muzzle brake. For Africa, the .375 H&H cartridge is still more readily available.

The .375 Ruger gives slightly higher velocities and is a better design. The tapered case of the .375 H&H does give superb feeding – an important consideration with dangerous game. In the dense jungle of the Congo if hunting the most difficult dwarf forest buffalo, or beautiful antelope the elusive bongo, a compact lighter .375 Ruger would be better. Imagine using a medium bore to bag a bongo and a dwarf forest buffalo!

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