Profiling – The Effects of Rifle Bullet Shape
2020 Ammo 0 Comments
Tailor ammunition choice to Hunting area, Species, Shot distances to Maximize Best OptionsSTORY BY PHIL MASSARO • PHOTOS BY MASSARO MEDIA GROUP
Not all bullet profiles perform the same, and you should choose the profile that best suits your hunting scenario. Looking at ammunition advertisements, or while reading articles on hunting or shooting, you will invariably come across terms that are used to describe the shape and/or profile of a bullet. Ballistic coefficient, sectional density, boat tail, secant ogive, flatnose, roundnose, hollowpoint; the list goes on and on.
Which design is best for your shooting or hunting needs? Looking back through the history of the projectile, the earliest jacketed bullets were roundnose designs, hearkening back to the lead bullet designs of the mid- to late 19th century.
At moderate ranges, these bullets offered everything a hunter or shooter needed: plenty of accuracy, a weight forward design that aided in straight line penetration, and a compact length to-width ratio that didn’t take up all sorts of room in the case. Near the turn of the 20th century, and especially due to the battlefield results of the Spanish-American War, the U.S. Army decided to revamp its choice of the .30-40 Krag, and settled on the .30-03, retaining the 220-grain round nose bullet of the Krag.
It would be only three years until the U.S. would follow the lead of European designers, modifying the ’03 case and utilizing a lighter, pointed spitzer bullet. A boat tail – almost as crucial as that pointed nose – helped to increase the aerodynamic properties of the bullet at longer ranges, allowing for a flatter trajectory and for better retained velocities as distances increased.
In fact, the boat tail showed up on the scene as early as 1901, to give you an idea as to how rapidly the science of ballistics was evolving. Fast forward to 2020, and you’ll see all of the above designs still on the market, and still doing well, each for its own reason. Let’s take a look at the benefits and downsides of the different rifle bullet designs to help aid you in your decision-making process.
THE ROUNDNOSE BULLETS – so popular among the classic cartridges and those who enjoy using them – can still make an effective choice for the hunter, providing the distances at which you intend to take game aren’t too great. For the intents of this article, I’ll include the flatnose bullets in this group as well, as they’ll perform much the same.
The major issue with roundnose bullets is that their ballistic coefficient
– the measure of how easily they will slip through the atmosphere
– tends to be low, and their velocities will drop off after 200 yards or so.
If you’re hunting inside of that number, and I’m certain that for most of us in the eastern part of the country this is true, these bullets pose no real handicap, as more than likely you are shooting a big game cartridge powerful enough to be zeroed at 200 yards.
The Hornady InterLock and DGX Bonded, the Woodleigh Weldcore, the Federal Power-Shok line, certain Sierra ProHunter bullets; all are good roundnose designs. I use them in the 6.5-284 Norma (a 160-grain roundnose is a formidable choice), the .308 Winchester and .300 Winchester Magnum, and the .318 Westley Richards, as well as the .375 H&H, .404 Jeffery and .470 NE, and I love the way they hit an animal. Upon impact, you can see the animal shudder, and I firmly believe the way the flat nose and round nose bullets transfer energy is a unique experience.
In addition to the closer shots in the Northeast, hunting in the African bushveldt rarely presents shots past 200 yards, so there are still plenty of applications for the older style of projectile. And they can be wonderfully accurate!
MOVING TO THE spitzer design, you will see a definite advantage in trajectory when the shots get longer. Classic designs like the Nosler Partition, the Sierra ProHunter, many of the Hornady InterLocks and SSTs, the Barnes TSX, and others represent what I refer to as a middle-of-the-road choice for hunters, as you will see the trajectory flatten out past 200 yards, and the amount of retained energy increase at longer distances.
The ogive shape most often associated with these bullets is still rather curved, so when maintaining the SAAMI- or CIP-approved overall length, the case capacity isn’t impinged upon too badly. I really like these as a choice for a general hunting bullet, as I try to keep things inside of 400 yards when hunting, and the true benefits of a boat tail over a flat base design don’t show themselves until around 350 yards. Even hunting globally, the amount of shots past that distance are few, unless prairie dogs are on the menu.
The boat tail spitzers, and especially some of the modern designs, are truly a thing of beauty. The science that goes into some of these bullets is astounding; they have nearly perfected the projectile. Both target and hunting bullets fall into this category, and for those who hunt the open plains or mountains, where windy conditions can pose a serious problem, this bullet type can be a game-changer. The long-range precision shooters – those who ring steel out past 1,000 yards and sometimes out past a mile – rely on this bullet profile for all of their work, as no other bullet design will give the reward at long ranges that the boat tail spitzer will.
Essentially, for target shooters, the conversation begins and ends with the boat tail spitzer. These bullets have the highest BC values, and though in the cup-and-core designs they can be prone to jacket/core separation, they are an excellent choice for those who routinely hunt antelope, elk, sheep, Coues deer and even mule deer in those open places where the wind and distance become a factor in making the shot.
DEAD FOOT ARMS
SO WHAT MAKES the most sense for you? Well, like I stated earlier, if you hunt the woods – where I spend most of my time – a roundnose bullet will serve. But there isn’t anything wrong with choosing a spitzer design or even a spitzer boat tail; just realize that you probably won’t see any of the accuracy or trajectory benefits at those short distances.
Certain bullet shapes lend themselves to certain cartridges. The .260 Remington (an excellent design) uses a longer case than does the newer 6.5 Creedmoor, the Creedmoor concept being to create a case short enough to use the long-ogive target bullets in a short-action magazine. The .260 Remington is too long to seat the longer bullets so that the case mouth hits the shank of the bullet and still adhere to the length dictated by the short-action magazine, and hence the success of the Creedmoor. If you’re a hunter who doesn’t need to push a bullet to 1,800 yards, the .260 Remington poses no handicap out to sane hunting ranges.
The same issue can pop up with the .300 Winchester Magnum; the designers moved the shoulder and case mouth so far forward in an effort to maximize case capacity that a good number of the longest target bullets can’t be loaded in the cartridge without exceeding the maximum overall length established by SAAMI. Had those designers ever envisioned the long-range shooting sports we all enjoy today, I’d be willing to wager the .300 Winchester Magnum would have looked much more like the .308 Norma Magnum, leaving more room for a longer bullet in the long action magazine.
Cartridges like the .350 Remington Magnum – trying to squeeze as much velocity as possible from a short-action rifle – simply cannot use the longest bullets in their caliber; it can seem silly to have to work so hard to attain velocity just to give up the use of most of the 250-grain bullets that made the .35-caliber’s reputation.
However, there are many who enjoy cartridges like this, and there are bullet choices that can become problem-solvers. Lastly, you may see that some classic cartridges use the lead-free copper alloy bullets, but those bullets may not be available in the heaviest bullet weights normally associated with that cartridge.
The difference can be the weight differential between a lead-core bullet and a copper alloy bullet; copper is much lighter than lead, and will – especially the spitzer boat tail designs – take up a whole bunch of room in the case.
For example, the .338 Federal, which is nothing more and nothing less than the .308 Winchester opened up to hold .338-inch-diameter bullets, can’t use the 250-grain copper alloy bullets; they are simply too long for the case capacity. Some hybrid designs – and the Federal Trophy Bonded Bear Claw and Trophy Bonded Tip come immediately to mind – blend a diminished lead core with a rear copper shank, and keep the weight forward to give an excellent best of both-worlds solution.
Examine your hunting area, or if you’re planning a trip to an exotic location, ask your outfitter about the average shot distances. You can then tailor your ammunition/bullet choice to the particular scenario in which you’ll be hunting, and maximize your experience.