Monday, July 1, 2013

Going Ballistic

Which cartridge is on the money?
One of the biggest mistakes I ever made while helping a customer choose a firearm was allowing myself to get caught up in a debate over ballistics. The debate wasn't with the customer I was helping. My customer was a novice about guns, just learning what was what, and in his early 40's, had decided to take up deer hunting. He was looking for a first ever bolt action rifle. Up till then he only had experience with a .22 lever action when he was a teenager, and had not since owned a gun of any sort. As I stood with him, looking at rifles and attempting to explain in near layman's terms what the practical differences would be between a .30-06 and a .270win, another customer joined the conversation.

"Those are some old-school rounds! What you want is a 7mm Remington short action ultra mag, or a .300 WSSM. I actually prefer the .338 WSSM myself, but I'm not recoil shy. But actually..." He continued on for a minute, rambling about various new (at the time) rifle chamberings, and began quoting ballistics charts and spouting some things about the principles and theories behind the various rounds that I knew to be bullshit. What made this worse was that in the midst of it he dropped the info (which was likely also bullshit) that he was an ex army sniper. What made this whole thing even worse was that my relatively clueless customer was standing there listening to all of it.

Then I made it even worser (as my 5-year-old would say). Instead of politely excusing myself and my customer to the ammo aisle to show him some examples, I allowed myself to engage the blowhard, know-it-all, BS-slinger in a debate over ballistics. By the time we were done, and Mr. Ex-sniper had relented - having to leave because his lunch break from the Jiffy Lube was over - my actual about-to-buy-a-rifle customer was confused out of his mind and didn't know what to think. I was back to square one, and possibly about to lose a sale from "over tech-ifying" the customer. (That's a sales term I coined that more sales people need to learn.)

Not that I was trying to sell the customer on a .30-06 or a .270, but rather I was attempting to teach him the basics of ballistics, in order for him to understand and help me figure out what chambering would work best for him, in his particular hunting situation. Instead I had helped to scramble his brains with tech details that are in all but the most extreme situations mostly pointless. Quickly realizing the problem I had just helped to create, I walked him to the ammo aisle and pulled out some boxes of rifle ammo and began again, with the basics. 30 minutes later I was calling NICS for his purchase of a new Ruger M77 in .243win with a Leupold VX-1 scope mounted and bore-sighted.

Turned out he had a pre-teen son who was wanting to try hunting, too. He decided they could share a good quality rifle at first instead of buying them each a cheaper grade gun like the Remington 710. Since they would be sharing, he went with a chambering of minimal recoil that was good enough ballistically for Alabama whitetail deer at moderate distances, and cheap and plentiful enough to allow them plenty of range time together before hitting the double ladder stand.

Hunting in 1937. Somehow, he still bagged
a deer with that old gun.

What it came to was that I had imparted to him my own philosophy that "old-school" doesn't mean "bad," and shiny-new-to-market doesn't always mean better, or better for you or your particular needs. What will work best in a chamber selection is not as easy as picking the hardest hitting, flattest trajectory, highest velocity round you can find. If it did, everyone would shoot .50 BMG and be done with it. That's absurd. There are more factors at play in selecting a chambering for your gun than ballistics tables alone. My customer had come to understand what his needs were, and with my advice, understood what would meet those needs. Ultimately he purchased a fine firearm that should serve him and his son well for years to come.


Whether you're shopping for a deer rifle, a home-defense carbine that can also pop coyotes in the back-40, or a handgun for concealed carry, targets, camping, or hunting, the variables involved in picking one include things like:

  • Is price per round a factor for you?
  • Is there sufficient ammo stock available in stores to keep you shooting? (almost irrelevant lately, but soon to be better, I think)
  • If you'll be traveling with the gun, will you be able to find ammo where you're going (commonality)?
  • Is recoil an issue? Who all will be shooting the firearm? Is recoil an issue for them?
  • Keeping zombie-science in mind, how common is the round? How likely are you to find some at a neighbor's house after he's been eaten? Is it a military chambering that you might find lying around a battlefield after TEOTWAWKI? To some people this is also a valid consideration.
Now, the only two points that require looking at a ballistics table prior to buying a gun:
  • How appropriate is the round to your purpose? Is it overkill? Is it powerful enough?
  • How flat is the flight path and how long-range of shots are YOU likely to make?
  • Can you handle an excessively arcing .45-70 and still be accurate, or do you really need a nickel plated Quigley replica Sharps breech loader for 500 yard shots at deer, just because you think it looks cool?
Okay, yes, that was three points. The third is more a personal rhetorical question I have been asking myself for many years. (And yes, I know, Quigley's rifle was a .45-110 paper patch in the movie. The actual rifle used for the long-range shots was, however, the more common .45-70 government chambering, which also happens to be the normal chambering for the replicas of the movie gun put out by various companies. Don't get me started on Quigley, because then I'll start thinking about Crazy Cora and things will surely go downhill.)

I seem to be getting off track. This article is about ballistics. It's about people going ballistic over ballistics, and obsessing needlessly over feet-per-second (FPS), muzzle energy (FT-LB), and arguing endlessly over the efficacy of ballistics gel testing versus real world application. For the relative beginner, who hasn't formed his or her own opinions on these points yet, what do you need to know? Well, assuming you can answer the first five issues yourself with simple research and some honest thinking, let's explain where to start with reading ballistics tables, and where to leave it be.


The Basics of Velocity and Energy: What is Bullet Power?

The short answer: Bullet Power is Energy at the Target.

Avoiding getting too technical with formulas and equations (if you want to learn way too much about this, study this wiki page about Kinetic Energy), there are still a few things you need to understand about the basic physics involved with what happens when you fire a gun.

The old saying among racers: "Speed doesn't kill, it's stopping suddenly that kills you."

This is true. Whether hunting animals or defending yourself against two legged animals, what you need to have plenty of in your bullets in terminal energy. That being, the amount of kinetic energy the projectile is carrying when it meets it target, and stops. The energy it carries will be transferred into the target, causing a shock to the system and physically destroying it as the projectile penetrates. How do you know how much energy your bullet has at the target?

OK, one quick basic equation...

In other words... given the mass (m) of an object (a bullet, or projectile), and its velocity (v), you can determine how much kinetic energy (E) it delivers to the target. Simply take the velocity given on the ballistics table for any given distance, square it, multiply that by the mass of the bullet, divide the result by two, and bam, there's your energy. Well, kinda. Let's back up.

It's all too much to do in your head unless you're a physicist with a 180 I.Q. and have nothing better to do. Consider this: The heavier the bullet (bullet weight is given in grains) and the faster it moves (velocity, usually given in feet per second), the more energy (destructive and penetrating force) it will dissipate into the target.


"The salesman said this doesn't kick at all."
A .30-06 for example (numbers here borrowed from a Federal Premium Ammunition ballistics chart), weighing in at 150 grains, traveling at 2,340 fps at 200 yards, will deliver a shock of 1,823 ft-lbs of energy to the target, assuming it hits it, at 200 yards. These numbers may seem meaningless to the novice, but they are points of debate for bullshitters everywhere. Many BS'ers will spout on and on about muzzle energy and muzzle velocity, and tell you their gun is superior to yours because those numbers are higher. BS. Muzzle velocity tells you how fast the bullet is traveling when it exits the barrel. That's it. So unless the gun is pressed up against its target, muzzle velocity is relatively meaningless. Likewise with muzzle energy. All that tells you is how bad your shoulder is going to hurt after you squeeze the trigger. It's the energy the bullet is carrying as it leaves the barrel. Every action having an equal and opposite reaction (i.e. recoil, or "kick" of the gun), the muzzle energy actually can give you a vague idea of how hard the gun will kick you. Some other things come into play here, too, like weight of the gun, diameter of the projectile (relating to air resistance, etc), and whether or not you have a recoil absorbing stock on your gun. But that's another topic really. Point is, muzzle numbers are useless. What you want to know is terminal velocity and terminal energy. In other words, what are the numbers at range?


What's Enough Power? What's Overkill? What's Right for Your Purpose? 

You can seriously study ballistics tables until your eyes fall out and your brain melts out your ear. Trust me, I've been there. But it's almost pointless. Suppose you're comparing one .30-06 round by one manufacturer to a different .30-06 round by a different manufacturer. Sure, you can see which one delivers the most energy and at what velocity at any given range on the table. But what's a significant difference? 200 ft-lbs? 100? 50? 10? It's all relative.

Example (The following ballistics tables are made up by me just now, and should not be used for actual comparisons or targeting at range):



Fictitious Ballistics Table for Hypothetical .30-06 Comparison. DO NOT USE IN REAL WORLD.
Bullet Weight (grains)
Velocity (FPS)
At distance (yards)
0
100
200
300
Energy (ft-lbs)
At distance (yards)
0
100
200
300
Drop (inches)
At distance (yards)
0
100
200
300
150
2900
2600
2300
2100
2800
2300
1800
1400
-
0
-3.6
-13
150
3000
2750
2500
2200
2900
2400
2000
1650
-
0
-3.2
-11



Studying my fictional .30-06 chart above, we can see that both bullets are 150 grains, yet, due to manufacturing differences in powder strength and quantity and the projectile design (shape), one is faster than the other. The faster one carries with it more energy down range. Remember that in the energy equation velocity is squared (multiplied times itself), giving it the upper hand over mass in determining the energy by calculation. So, we have at 200 yards one moving 2300 fps, while the other is still clocking 2500 fps. The faster one yields 200 ft-lbs more energy at 200 yards. (I repeat, these numbers are fictitious. I have NOT done actual calculations here.) So is the 200 ft-lbs a useful difference?

Consider that 200 ft-lbs of energy is roughly what a .38special handgun projectile delivers to its target at 25 yards. (This is true, not made up.) So, shooting a deer at 200 yards with the superior round above should give a similar effect to shooting it with the other one PLUS a .38 revolver from 25 yards away ... simultaneously. Make sense? Now, here's another twist for you... what about a .270?



Fictitious Ballistics Table for Hypothetical .270 Comparison. DO NOT USE IN REAL WORLD.
Bullet Weight (grains)
Velocity (FPS)
At distance (yards)
0
100
200
300
Energy (ft-lbs)
At distance (yards)
0
100
200
300
Drop (inches)
At distance (yards)
0
100
200
300
130
3050
2800
2600
2370
2700
2300
1900
1600
-
0
-2.9
-11
150
2850
2650
2450
2300
2700
2350
2050
1750
-
0
-3.4
-12


Aha. The above made up chart about a .270win comparison shows similar results to the .30-06. But, wait. The velocities maintain higher as the distance increases, and thus, so do the energies. Why? Well, a .270 is thinner than a .30-06. It's a smaller caliber, so the ballistic coefficient (something I'm NOT getting into here) is higher, or it's air resistance (coefficient of drag), is reduced, so it is slowed less by the friction caused by pushing a chunk of copper through the air.

Also of note, the bullet drop (the effect of gravity) is less with the .270, though barely. Why? It's moving faster, so it got there quicker, so it has not fallen to earth as far because it hasn't been flying for as long of a time.

So, the .270 is faster, flies flatter, delivers more energy with the same payload of mass. The casings are roughly the same size, too. So does this mean the .270 is superior to the .30-06? Winchester thought so in 1925 when they created the .270 based on a necked-down .30-06 Springfield. Many people do think it's superior. Alas, many people disagree. Why? Simply put: the .30-06 makes a bigger hole.

True, the difference in diameter is only .03 of an inch. How much difference could it make? Depending on your target, lots. For one, because of the additional girth, the .30-06 can carry more weight in its projectile given an identical length. Not just mass, but matter. Stuff, lead core...to spread open wide and rip and shred. Also, it can hit harder, with a more solid impact than the .270, because of its larger diameter. Again, it's not much harder, but it is some. So even though the .270 delivers more energy, much of it is going to the penetration...the puncture. The .30-06...more of it is going to a punch, and slowing down. Granted, these two are so close that not much difference can be found until you get to larger weight differences like a 130 grain .270 versus a 180 grain .30-06.

The difference in surface impacts of bullets is a controversial issue. Many people dismiss it, many people live by it. I've read reports and heard first hand and second hand accounts of both cops and E.R. doctors who have all said that if it's a gunshot wound to the chest, a larger caliber is deadlier because it hits harder, like being punched brutally, damaging organs by shock more than just penetration. Head wounds are slightly different story I'll get into in another article sometime. Now, when looking at hunting rifles being used on deer, however, does this still apply?

Isn't a deer similar in size and mass to a man? Well, a small man. But, wouldn't it still make sense that the same concept applies? Yes, except for one thing...accuracy. At range, if you're shooting a .270, with its roughly 10 inch drop at 200 yards, or a .45-70 with its godawful drop of more than twice that, then even if the .45-70 is carrying more mass, with a much larger surface to punch with (although ironically much less energy because it's moving so much slower), then even though the .45-70 will knock that deer on its ass if you hit it solid broad side in the chest, the question becomes, will you hit it? Being that you're more likely to have accurate shot placement with the .270, and are less likely to miss the deer entirely, it stands to reason that you're more likely to get a kill with it than with the .45-70. Now, if you're Matthew Quigley, it doesn't matter. To most folks, it kinda does.

What have I proved here? What point have I made? Let me ask you this:

If you shoot a deer through the lungs with a .270, another deer with a .30-06, another deer with a
Which is better for you? Maybe none of these?
.45-70, and another deer with a .243 ... which deer is deadest?  Ah. There's the rub. For whether 'tis shot with a pellet gun or canon, there are other factors that make one better than another, not the pellets or canon balls themselves. It's how they're used, and what situation they are brought into.

Find a gun that you're comfortable shouldering or gripping; one that you're comfortable operating; one that feels right to hold. Select a chambering caliber that isn't too much recoil for you, that is an accepted convention for the application you intend (hunting deer, hunting varmints, self defense, long range targets, tactical competition, etc) and roll with it. Look to calibers that are common, and you'll have better luck not only finding ammo, but finding a greater variety and at often times less cost. Don't obsess over whether a .30-06 is better than a .308 or a .270. Don't worry over whether a .357sig is superior to a 9mm+P.  It's splitting hairs. It's pointless and maddening. Find a caliber you like and then try different examples of ammo from various manufacturers to discover what works best in your particular gun. Some ammo is perfect is one gun and sucks in another. Different guns like different foods. So even if you buy a .300 win-mag, you might not get to shoot the ballistically hottest ammo product because it might not be accurate in your particular rifle. Don't sweat it. .300 win-mag is .300 win-mag. At that point it's more about projectile design than ballistics (another article for later).

Don't go ballistic over ballistics. Obviously, don't bring a howitzer squirrel hunting, and don't take a .22 hornet deer hunting. Use some sense in appropriate weapons for the purpose. There are common conventions, like the .243 being minimal for deer, the .375 H&H being minimal for rhinoceros, etc. The .30-30 and .30-06 together have killed more deer in the United States than all other chamberings combined (so I read once, somewhere.) Most people dismiss the .30-30 nowadays, because it's "not enough." BS. It works as great as it always has. Latest is not always greatest, and in my book, more expensive rarely is necessarily better just because it looks better on paper or has more shine and cache to it.

Think about all of the variables and find something that works for you, in your situation, and if you're just not sure what to pick, go with the common conventions. The old stand-by's. If you're not sure what is a common caliber for your activity, ask a salesperson at a gun store, or leave a comment here and ask me. I don't mind answering a specific question. Just don't ask the sales guy, or me, what's "best" for your activity. That's a loaded question.

4 comments:

  1. Good stuff. So you're saying I should buy a .30-06 right? lol

    ReplyDelete
    Replies
    1. Yes, exactly. lol

      No...but maybe.

      Clearer?

      Delete
  2. Ha! I get it! "Loaded" question! Hoo!
    This is seriously the best article I've ever read on this subject. Man, the BS out there is astounding. Thanks for clearing up so many issues (I can't tell you how many times I've sat there wondering why I should care about muzzle velocity.)
    Wow. Thanks!

    ReplyDelete
    Replies
    1. Glad you enjoyed it and learned something! My mission is complete.

      Delete

Keep it clean and courteous people. Lively is good, mean spirited is bad. Thanks for participating!

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