Target Sports

HANDLOADING TOPICS: SPORTING BULLETS

Created on 30th June 2009

In his final part of a study on the unsung bullet, LAURIE HOLLAND covers those used on quarry

This final part of our overview looks at high-velocity rifle bullet wounds and expanding designs for sporting cartridges.

The wounding power, in particular the ‘man-stopping ability', of small-calibre military rifle cartridges was an issue for many years. This came as a surprise, since penetrating pine boards a set distance apart was the contemporary terminal effectiveness test, and these cartridges produced a step-change in performance. For example, the American .30-40 (220gn 0.308" RNFMJ, 2,066fps MV) penetrated 58 7/8" thick planks on average compared to 18 for its BP predecessor (.45-70 US Govt. 500gn 0.458" lead RN, 1,300fps MV). However, experience in the field - especially against ‘savages' - showed penetration didn't guarantee incapacitation. In fact, the reverse was true, as performance was poor compared to that of heavy, slow BP cartridge projectiles. Too many charging North-West Frontier tribesmen and their bladed weapons got into British lines, despite .303" hits en route. Some troopers demanded .450" Martini-Henry rifles be reissued; others filed the jacket tips off bullets, a risky practice that could cause a bullet to fail in the barrel. The Dum Dum soft-point followed by Mk II to V expanding hollow-point designs provided solutions, but were subsequently outlawed.

Inhumane

The problem was that long round-nosed bullets were over-stable, so they inflicted little damage and left a narrow wound track. (Although if the bullet hit the head, spine, major organ or large blood vessel, it stopped people, of course.) Things moved on when the Germans introduced their 7.92mm S-Patrone with its sharply pointed bullet in 1905, and others followed.

Although designed to improve external ballistics, it was subsequently found base-heavy ‘spitzer' bullets tumbled in the body, producing much more severe wounds. The British 0.303" 174gn Mark VII went further, with a void ahead of the core filled with light material to move the centre of gravity even further back.

More recently, the original (M193) 5.56mm cartridge gave a 55gn 0.224" FMJBT bullet 3,250fps and was frequently found to inflict horrendous wounds in the Vietnam jungle war with its short-range firefights. Bullets tumbled on entry, which, coupled with still high terminal velocity, produced enormous lateral stresses, leading to jacket failure and then complete break-up in an explosive disintegration after a few inches of travel. Medical workers from neutral countries reported the effects of the ‘inhumane bullet' back to their governments, and there was a first-class international row.

The .30 bites back

Military interest in bullet effectiveness virtually died in the final decades of the 20th century, with new crew-served and high-technology weapons systems seen as the way forward. With the value of the rifle downgraded, reducing recoil and cartridge weight took precedence over range and effectiveness, with training also now restricted to 300yd. Compromise smallarms designs using a heavy (62gn) bullet version of the 5.56 were adopted by NATO, and our MoD tried to withdraw the 7.62mm ‘Gimpy' machine-gun for logistical reasons.

However, interest in smallarms bullets has resurfaced with a vengeance thanks to Iraq and Afghanistan, where marksmanship skills and 5.56mm performance have been found wanting in theatres that produce 300m+ engagements. In response, the US introduced the SDM (Squad Designated Marksman) concept: a half-way house between rifleman and sniper, each rifle-section having one specially trained and equipped member. All sorts of rifles were initially resurrected, but the AR10-based 7.62mm XM110 or SASS (Semi-Automatic Sniper System) from Knight's Armament Company is now being issued as standard. (Incidentally, unlike in the UK where target shooting is deemed to have no national security value, American High-Power Service Rifle competitors work as volunteer SDM instructors: the XM110 started life as a target shooting rifle, and 7.62mm M118LR ammunition is loaded with Sierra Match King bullets.)

Dem bones, dem bones...

Readers who've read up on bullet wounds or are deerstalkers will mutter at this point that predicting that bullets behave in this or that way doesn't necessarily work out in practice. Quite so! Tissue density varies; ordinary clothing, never mind a soldier's webbing and kit, can affect performance. The target may be moving as the bullet strikes. The result is that terminal behaviour is unpredictable.

While tests use homogeneous gelatine blocks, bodies contain bones of varying size, strength and density, as well as joints with ligaments and blood vessels. Striking one creates a new set of variables depending on the size and nature of the bone; point of impact; the bullet's shape; stability; and velocity. It can drill a clean round hole, or in other circumstances cause the bone to fragment, producing high-velocity splinters that inflict major trauma on soft tissue or organs out of all proportion to their size and weight. Psychological factors play a part, western conscript soldiers generally giving up with anything other than the most minor gunshot wound - a major factor in early small-calibre bullet ineffectiveness in colonial days, with ‘native' insurgents motivated by extreme religious conviction being unaffected or even spurred on by non-disabling wounds. The suicidal jihadist is not new!

Sporting bullets

The sporting bullet faces a hard task. It must still hit the target at the point of aim, and users'accuracy expectations are now very high. Unlike the match bullet, a part of its job only starts with the hit, requiring a new set of properties to inflict catastrophic disruption on the animal's circulatory system. Most are expanding types and come in various shapes - round-nose; pointed/semi-pointed; flat-nose (for leverguns with tube magazines); hollow-point; and at the rear, flat-base and boat-tail forms. A variant of the hollow-point is increasingly popular - like designs such as the Nosler Ballistic Tip and Hornady SST, which have a pointed polycarbonate plug inserted into the nose. As well as improving the BC, tips aren't deformed by battering the front magazine wall under recoil (a problem with conventional ‘spitzer' lead points) and expansion can be designed to be rapid and substantial, with the plug forced hard back into jacket and core on penetration. Our old friend the non-expanding FMJ is still around in sporting guise for two very different types of quarry - small fur-bearing and edible animals, and the largest of Africa's dangerous game. The rationale in the former case is that an expanding bullet makes a large exit hole, reducing the value of a fur pelt, or destroys all meat in small game. FMJs used on big, dangerous quarry are inaccurately called ‘solids', but are actually heavy blunt - very heavily constructed versions of the familiar two-metal form. John Rigby came up with definitive designs nearly 100 years ago with thick steel jackets coated with gilding metal, still manufactured today by Woodleigh in Australia. True solids are available from Barnes, A-Square and others, and are machined from copper alloy, or even naval bronze.

For the other end of the quarry size scale, there is a huge choice of ‘varmint' bullets. Designed for non-edible pests, they produce instantaneous massive expansion, the thin jacket exploding outwards to maybe three times the bullet's original diameter. Parts of the jacket, and most of the lead core, will disintegrate inside the animal with such violence that massive trauma is inflicted on the circulatory system and every organ inside a small animal. This sounds terrible, but is humane as it minimises the chance of the non-fatal hit that sees the creature disappear over the horizon or down a burrow to die unpleasantly. Because of the nature and habitat of varmint species, bullets need to be capable of producing match accuracy and loading at high velocities. This has resulted in a move to light-for-calibre models in recent years - 35 and 40gn in 0.224"; 55gn for 6mm; not to mention the 32gn load in the .204 Ruger at nearly 4,200fps MV.

Medium game

‘Medium' covers a large spectrum - from 20lb muntjac and roe to red deer stags 10 times that weight here, and still larger in continental Europe and North America. 6.5 to 8mm calibre cartridges used on such species may also be suitable for animals in the next classification, ‘large game': elk, moose and African plains animals that run to the 1,000lb mark provided suitable bullets are used, although many stalkers prefer larger calibres in the .338" to 9.3mm (0.366") range. This also applies to wild boar - large, tough animals that can weigh up to 500lb, and are dangerous if wounded.

The factors determining bullet performance, and hence whether or not the stalker obtains a clean and humane kill, are as follows: velocity; bullet weight and construction; quarry position (broadside or quartering); and correct shot placement. Even our largest deer are fairly narrow across the chest cavity, so enormous penetration is not required in a broadside shot, but there is a good chance of the bullet hitting bone on the way in. (This assumes the stalker is aiming for the ‘kill zone' that encompasses the heart, liver, lungs and major arterial complexes.)

What do hunters want from deer bullets? Some just want them to work without destroying too much meat, and don't care what they look like afterwards, but many, especially in the USA, have become obsessed with bullet ‘performance'. The current mantra is full expansion to twice the original calibre or more in the classic mushroom shape and staying intact if a large bone is hit, then penetrating through it through to the ‘boiler room'; plus 90% or more weight retention. Some want fantastic penetration, to shoot animals running away up the rear and still have bullets reach the chest cavity! A few want the bullet to remain in the animal ‘so it expends all of its terminal energy inside', while most want a large exit wound and heavy blood loss to track a wounded beast, or one that runs 100yd on adrenalin before collapse. Almost everybody wants the bullet to stay in one piece - jacket and core separation being anathema.

There is a risk in all this that theoretical considerations, and advertisements with pictures of perfectly mushroomed bullets that have retained 99.9% of their original weight, distract shooters from the object of the exercise, or have them buying an expensive ‘bullet of the month' they don't need. There is a story about an American hunter who was, sensibly, advised to use Nosler Partitions on his first elk hunt, which illustrates this. The Partition, the earliest American specialist bullet, is designed to have its front core expand violently, often fragmenting, while the rear section is nearly indestructible and ploughs through everything. Anyway, the man appeared in the gunshop on his return and produced a much-truncated recovered bullet - angry that he'd been advised to use an ‘inferior' product that had lost a lot of weight. Assistant: "What about the elk?" Customer: "It collapsed on the spot." Assistant: "And exactly which bit of its falling down made you notice the bullet had failed?"

Traditional

Conventional expanding designs are made the same way as the Lapua Scenar illustrated in the last issue: a gilding metal ‘coin' drawn out to form an elongated cup, the lead core inserted and the open end of the cup, with swaged into the bullet shoulder and nose. While the match bullet has a tiny hollow point/meplat, a sporting model will either have a large cavity here, or have the core protruding out of the jacket and swaged into the desired nose shape. The early 6.5-8mm calibre expanding bullets were made for the service cartridges of the day, and generally adopted the same weights and forms as military FMJ bullets, albeit constructed ‘in reverse' with the exposed core at the front. As such, they were invariably round-nose and long/heavy for calibre: 160gn 6.5mm, 173gn 7mm; 220gn for .30; and so on. MVs were mostly in the 2,000-2,300fps range. They offered fantastic penetration, but weren't so good at expanding. Putting that right, with thinner jackets and larger exposed lead tips, often meant over-expansion if a large bone was struck. With nothing keeping jacket and core together except a friction fit, such an event could produce separation and break-up before the bullet reached vital organs. This conundrum afflicted most manufacturers throughout the first half of the 20th century, although Wilhelm Brenneke had invented the twin-core TIG and TUG models before WW1: the first ‘controlled expansion' designs, still made by RWS today.

What allowed these simple designs to generally work well was their low velocity, which didn't overstress the bullet after entry, allied to great length, hence high SD (Sectional Density, the ratio of bullet weight to diameter). While high SD benefits the long-range target shooter, through helping the bullet to provide good external ballistics performance, it is also important to the big-game hunter who needs deep bullet penetration. These blunt round-nosed low-velocity bullets therefore performed superbly on large animals. Craig Boddington recounts experiences in Africa with ancient Kynoch .318 Westley Richards cartridges (250gn 0.330" RN FMJs and SPs at under 2,200fps MV) on zebra and wildebeest in his book Safari Rifles, saying the rifle was one of the deadliest he'd used and nothing seemed to stop the .318's long, heavy bullets.

As bullet weights dropped, pressures and velocities rose, and pointed designs became the norm, manufacturers improved performance with tapered jackets - thick/heavy at the base, and thin and relatively weak at the nose to promote expansion. The old bugbear of jacket/core separation was largely overcome by a variety of rings and belts on jacket inner surfaces to hold the two components together, often reflected in proprietary names such as Core-Lokt (Remington) and Interlock (Hornady).

‘Deep divers' and high velocity

That 1,900-2,300fps terminal velocity bracket seems to be magical for long heavy bullets, with 285gn 9.3s being particularly deadly on big soft-skinned game animals at this level. Look at the ballistics of African big-bores (.40 to .70 calibre) - ancient and modern - and you'll find MVs are in the 2,000-2,400fps range, with a larger calibre, heavier bullet and more ft/lb ME used as the task becomes harder. (The sole, higher MV, exception is a Weatherby cartridge - now there's a surprise!)

Broadly speaking, bullets are designed with two criteria in view - the size/nature of the quarry and terminal velocity. Taking the popular .30-calibre as an example, American cup and core bullets have been designed for .30-06 Springfield velocities and likely shooting distances (say 75-250yd) since before WW2, so they cater for terminal velocities in the 2,300-2,600fps range with 180-grainers. Drop much below the bullet's comfort zone, and it won't expand properly; exceed it significantly and over-expansion is likely, or even break-up.

It's the latter situation that has produced a raft of ‘controlled expansion' bullets, thanks to a huge increase in the use of high-velocity magnum cartridges, especially in North America. The story starts in 1946 with John Nosler, then a successful road haulier, putting four 180gn bullets from a .300 H&H Magnum rifle into a mud-caked British Columbia moose and having every one break up, with a subsequent couple of shots finally working. (The H&H was loaded a bit hotter in those days, with 180s at 3,000fps MV.) He went home, designed the Partition, and started making it in the company workshop - Nosler Bullets grew from that. As noted, the Partition has a ‘soft' front and ‘hard' rear - made deliberately that way, although it offends those who worship maximum weight retention.

The Swift A-Frame also uses the two-core format, but is tougher up-front and has that other feature of modern ‘designer' bullets that retain a lead core or cores - the front core is bonded to the jacket, so they mushroom out together and don't shed any bits in the process. There are now several premium bonded bullets - Hornady Interbond, Nosler Accubond and Swift Scirocco. We also have designs without a lead core at all - the oldest is the extruded solid copper Barnes X, now joined by the Triple Shock X and Maximum Range X (the ‘X' comes from their being designed to expand with four big ‘petals' in an X-formation). Lapua has recently joined this club with its Naturalis. All such bullets have deep hollow-point cavities to provoke expansion. The Lapua has a plastic nose plug. The Trophy Bonded Bearclaw (the first design to bond components together) and Prvi-Partizan GROM are hybrid HP designs that have a small lead core in the front half of the bullet, with most of the body formed from solid copper. Although there are variations in how ‘tough' these designs are, they're generally designed to handle high velocities and provide very deep penetration on large game, so they don't expand as fast as traditional types. They can be used on deer from a .308, but make a relatively small wound channel compared to a cup and core Sierra or Speer - so we now have two groups of cartridges and bullets, the dividing line in this calibre being between .300 H&H Magnum and .300 Remington Short Action Ultra-Magnum performance. (See velocity table - note there are now far more designs producing performance above the cup and core bullet comfort zone than within it.)

Further reading

This look at wound ballistics and expanding bullets barely scratches the surface of these massive subjects, with several books in print on large African cartridges/bullets alone. Readers interested in the subjects might find the following useful.

Wound ballistics

There are many textbooks, the most widely available being Gunshot Wounds: Practical Aspects of Firearms, Ballistics, and Forensic Techniques Second Edition by Vincent J M DiMaio, but its US price is nearly $120. Much useful material can be obtained free by typing ‘Martin L Fackler’ or ‘International Wound Ballistics Association’ (the former founded the latter) into Google. This will produce scores of hits on the subject.

Bullet performance

Vihtavuori Reloading Manual 4th Edition (new edition, available from Tim Hannam or your local handloading supplier) – article entitled ‘Big Game Hunting with Ammunition made in Finland’ by Adam Mykkänen – about experiences of bullet performance obtained over decades of hunting Finnish moose with the 7.62X54R and 9.3X62mm cartridges. (A much upgraded manual, highly recommended to those who use Viht powders.)

Rifle Bullets for the Hunter: A Definitive Study: a multi-author study edited by Dave Campbell offering a complete rundown on sporting bullet design and performance, cast as well as jacketed, including testing and categorisation using the Bullet Test Tube home ballistic testing kit. Available from Sinclair International, Amazon.com, or direct online from the publisher, Ballistic Technology of Princeton, West Virginia – www.thebullettesttube.com (ISBN 0-9789580-0-4).

Going Ballistic by John Nosler, as told to Gary Lewis – John Nosler’s autobiography. Published by Gary Lewis Outdoors of Bend, Oregon ISBN 0-9761244-0-8. (Available through Amazon.com.)

Safari Rifles and American Hunting Rifles (paperback) by Craig Boddington. Both books published by Safari Press Inc, of Huntington Beach, California. (Available through Amazon.com.)

Dangerous Game Rifles by Terry Wieland, Countrysport Press of Camden, Maine ISBN 0-8927269-1-1. Vast amount of information on large-calibre African cartridges, bullet types and their history, development and performance. (Available through Amazon.com.)

African Rifles and Cartridges by John ‘Pondoro’ Taylor, published by Safari Press Inc and currently available new from Amazon.co.uk for only £15.64. The definitive book on large African game cartridges and bullets, very old but still relevant.