We often hear of a rifle’s killing power, or a “stopping rifle”. While we understand the intent of such expressions, we know that a rifle does none of those things. Of course, it’s the bullet that kills, wounds, stops or even misses the game animal. The rifle is built to fire the bullet that is intended to kill or stop said creature. Depending on the expected target, we choose a rifle that will fire a suitable projectile. If it’s a big, tough and potentially dangerous beast, we want a rifle commensurate for the job, and that means rifles chambered for cartridges capable of handling bullets of appropriate construction, caliber and shape. (Left click on photos for a better view.)
We’ve already had a couple thousand words regarding construction — no doubt a million words wouldn’t suffice for some folk. For others, a couple hundred might be too much. The point being that bullet construction will continue to be debated into the foreseeable future, as it has in the past, as to what is best for a particular hunting task. But, in my way of thinking, we have the best choices today than we’ve ever had in bygone days.
Next:
CALIBER
That’s the size of the hole in your barrel, sometimes designated by hundreds of an inch, or thousands, or even fractions. That originated with the British, then was adopted by those of the British colonies, and the Americans. Others of European influence use the metric system — i.e. millimetres or mm. The larger the hole in your barrel means the bullet will be larger and usually heavier. That in turn should mean a larger permanent wound channel, all other things equal.
The weight of the bullet in relation to its caliber determines its sectional density, and has a specific influence on its ballistic coefficient and penetration. Caliber is measured in the grooves at 180 degrees from facing grooves. Hence, a .308″ caliber shoots a bullet of .308-inch diameter so that the lands of the rifling will cut into the surface of the bullet for stability as it rotates down the bore, spinning like a top — the purpose of the rifling twist-rate. Of course, we already know all that, right? But the rate of twist is very important in using heavy-for-caliber projectiles that may tend to be overly long in today’s world of monolithic bullets. Ergo: the twist rate must be capable of stabilizing a long – heavy bullet. That may mean a faster rate than normally found in a factory rifle.
And, to emphasize, once again, this site is primarily about Big Bores that fire big bullets!
Big Bores, in general today, are considered to be .40-caliber plus. So in the consideration of suitable bullets for big, large and dangerous game, we are thinking heavy, wide and well constructed bullets.
As per our last blog (P1) on this theme: construction should not be taken for granted, but suited to the task! After that comes bullet weight.
In deciding on caliber we need first to know what cartridges are available in that caliber. A .35 Remington is in no way comparable in ballistics to a .358 Norma Magnum, for example. The .35 Remington holds a maximum of about 42 grains of a medium powder under a 200 grain, and grants an MV of around 2100 fps/1958 ft-lbs, whereas the .358 Norma Magnum will use about 75 grains of a slower powder to propel the same bullet at 2900 fps/3734 ft-lbs; almost twice the powder consumed for nearly twice the energy!
So it’s obvious that we should be considering the cartridge as well as the caliber, if we’re thinking big dangerous stuff! In some cases in Africa, for instance, a .375-cal is minimum for DG. But also joules are a consideration. A .375 Winchester producing about 2000 ft-lbs at the muzzle = 2830 joules (500 joules = 386.78 ft-lbs). Most big and dangerous game in Africa require over 4000 joules to qualify. So a .375 Winchester is not the same thing as a .375 H&H that easily makes 6000 joules. The 9.3 x 62 and 9.3 x 74R are legal in many African countries for large and dangerous game. My 9.3 x 62 can make up to 5960 joules. So the cartridge is at least as important as the caliber, and in some cases (pun unavoidable) more so.
The important thing is that there are plenty of excellent component bullets for the handloader that are available from several sources to fulfil both requirements and expectations in hunting large and dangerous game while using medium and large bores.
SHAPE (profile)
While a bullet’s weight and caliber determines its sectional density (SD), it’s construction, weight, caliber and profile determines its ballistic coefficient (BC).
For instance: a bullet fully constructed of copper will be longer than one fully made of lead, or lead and copper, if the weight, caliber and BC are the same. (The pic on the left has two 350gr/.458″ bullets side by side near the center. On the right is the 350 TSX and on its left is a 350gr Hornady. Note their contrast in length.) The obvious reason being that lead is more dense (heavier) than copper, or copper alloy. So it takes more “space” in the cartridge case in using a monolithic bullet of copper (or copper alloy) than it does for one that does the same thing in ballistics if most of its weight is lead. There are exceptions to that general rule which is explained in the following paragraphs.
There are advantages and some disadvantages to each depending on intention. For example, I’ll not use the Barnes TSX’s in my 9.3 x 62 because their length takes up room in the cartridge that should be reserved for powder, if COL is nominal as in bolt-action rifles. One the other hand, the Noslers of the same weight have much better BCs and are shorter, allowing more of the best component powders to be used.
Still, the bullets favored (in general) for my .458 Win Mag are the 300, 350 and 450 TSX’s. Because of the long “freebore”, I can seat them out as far as the grooves in the bullets’ shank allows — that is the bottom groove, or cannelure, which takes no more space from the case than any component bullet made of pure lead or copper and lead — they all are seated to the same depth in the case making the COL longer for some than others.
So, if you get the gist of matters here, a bullets’ shape, or profile, may not only affect its BC (downrange punch) but how much of the best powder may be useful. If it’s too long, it will not allow the desired or expected MV, which will determine downrange efficiency, even though the BC may be superior to another of the same weight.
Another example: Several competing companies are now producing LR bullets (LR = long range). Not only are they intended for long-range shooting of game, but they are LONG! Keep that in mind if you load them, thinking they would be best in shooting game at, say, 450 yards. They might have a higher BC, but if you loose 150 fps in MV due to cramped space in the cartridge, because of an action that is “standard” for the cartridge, your “streamlined” bullet may be no better than another of a more normal profile for the same thing, and possibly less so! Do a ballistic profile.
Construction and caliber are significant bullet entities, but, depending on possible diverse ranges in the same hunt, so is the aerodynamics of your projectile.
The majority of my big game hunts have imposed ranges of less than 200 yards, but not all. In previous blogs I’ve described several moose hunts in the north of our province where potential distances could range between less than a dozen yards to well beyond 600. The rifle and bullet was always the main concern. “Rifle” meaning cartridge. On my first trip, I was not fully aware of the physical context, except we would be hunting from a lodge on a lake about 5 – 6 hours from home. I took a .338 Win Mag and a .45-70 as backup. The .338 got to see most of the country that consisted of very variable terrain from high ridges to small lakes, streams, marshes and bogs. And all of it (other than the lakes, streams, marshes and bogs) heavily wooded. I recall sitting in a tangle of thick bush about 2 to 3 feet high for one morning in a likely spot on the edge of the finger of a small lake, watching for moose on the far side. Range could have been very variable. Directly across was approximately 250 yards, but to my right was more like 1/4 mile. I was loaded with 250gr Sierra BTs at a tad under 2700 fps. They had a thick jacket of 0.050″ in the base and shank, and 0.026″ at the mouth, with a BC of .587 above 2300 fps. Recommended hunting ranges = 100 to 600 yards. I figured there wasn’t much that could be added to that to improve matters for such a hunt — and I was probably right at that time… except for one miserable “fly” in the perfume! That being the weather! It rained… I mean constantly for three days and the two-piece walnut stock on my beloved Sako Carbine, soaked it in! I had to dismantle the stock from the rifle each evening for a dry-out, then reassemble it early the next morning! Did I really know where the poi would be after that? No, not really.
Everything can be perfect, even the bullet… But the weather can spoil those beautiful handloads and the equipment that shoots them! Nonetheless, I continued to be optimistic that given a chance, I made the right ballistic choice.
Let’s see the ballistic potential of that load compared to a 250gr RN:
Cartridge: .338 Win Mag
Bullet: 250gr RN Hornady (some might choose it thinking it better for moose)
BC = .291
MV = 2700 fps/4046 ft-lbs ( Traj. = -1.6″)
100 = 2400 fps/3197 ft-lbs (Traj. = +3.0″)
200 = 2120 fps/2495 ft-lbs (Traj. = +1.57″) zero @ 226 yds.
300 = 1860 fps/1920 ft-lbs (Traj. = -7.59″)
400 = 1630 fps/1475 ft-lbs (Traj. = -26.74″)
Comments: Had I decided on this bullet for my moose hunt, I’m sure it would have been a good choice to about 300 yards, and that’s farther than most moose are taken. But what if a big bull moose had peaked its head out on my right side at 400 yards? Well, it was a bolt-action loaded with four… that may have worked, but there are too many doubts. Would the bullet have expanded? And trajectory? And what if the first shot allowed it to get into the lake? And…
Hornady does make a much better 250gr for a context such as I’ve described – a 250gr Interloc SP-RP with a BC of .431. Personally, I’d have no reasons against using it, except the Sierra had a heavier jacket and much better BC.(The 250 Sierra is 3rd from left and the Hornady is seventh.)
But what about the load I did choose?
Bullet: 250gr Sierra BT
BC = .587
MV = 2700/4046 ft-lbs (Traj. = -1.60″)
100 = 2545/3595 ft-lbs (Traj. = +3.0″)
200 = 2395/3184 ft-lbs (Traj. = +2.25″) zero @ 245 yds.)
300 = 2252/2815 ft-lbs (Traj. = -4.51″)
400 = 2113/2478 ft-lbs (Traj. = -18.03″)
Comments: Whatever our thoughts might be about kinetic energy at impact, there’s no question in my mind that it is a factor — perhaps not as much as generally believed, but 2478 ft-lbs of KE is a real factor, and 1003 ft-lbs more than the 250gr RN at 400 yds can’t be ignored.
(From where I took this photo, it’s about 400 yds to the opposite shore line at about 3/4s the distance from the left edge to the right edge of the pic.)
Bullet SHAPE (profile) undeniably matters!
Til the next,
Shalom
BOB MITCHELL
