Tag Archives: Smith & Wesson

Ballistics 101

What is “Ballistics?” “What is Muzzle velocity?” “What is ft/lbs energy?” “How does barrel length effect muzzle velocity”? “Do bullets travel in straight lines”? “What does {point blank} mean”?

Simply put, “Ballistics” is just a MEASURE of a bullet performance-when it leaves the gun (internal ballistics), while it is in flight (external ballistics), and when it impacts a target (terminal ballistics). Let’s take a look at these categories AND how to judge a bullet’s performance based on looking at its “ballistics”.

Internal Ballistics

Internal Ballistics is a numerical value that has to do with PROPULSION and ACCELERATION. You usually see Internal ballistics expressed in terms of “Muzzle Velocity” and “ft/lbs” of energy. The muzzle velocity is measured by a radar device that sits a few feet in front of the gun. GENERAL RULE of THUMB. The longer the barrel, the higher the muzzle velocity for a particular caliber. For example, the muzzle velocity of a 9mm being shot out of a 5 inch barrel will be HIGHER than the same bullet being shot out of a 3 inch barrel. This is occurs because of two basic reasons.  Firstly, the bullet is no longer assisted by the spiral grooves inside of the barrel once it exits the barrel. Once the bullet leaves the barrel it is relatively “independent” and is left at the mercy of the wind, GRAVITY, air friction, humidity etc. Secondly, the rapidly expanding gases inside the chamber also play a critical role in propulsion and acceleration. Once all of these high pressure gases are expelled, the bullet is left independent. Muzzle velocity IS THE FASTEST POINT at which the bullet will travel. The bullet will get slower as it flies down range (just like a football in flight).

Figure B1

Internal Ballistics Chart for common handgun calibers. NOTE. This ONLY gives you how the bullet behaves upon being propelled out of the gun. This is probably the most commonly referred to source of HANDGUN bullet power because handguns will be used at short ranges.

External Ballistics

External Ballistics is an observation of how a bullet behaves in flight. BULLETS DO NOT TRAVEL IN STRAIGHT LINES. (see figure B2 below) Bullets travel straight when leaving the gun, they rise, and then they begin to “drop”. GRAVITY IS A BULLET’S BIGGEST ENEMY. If you were to draw a line that represents a bullet’s flight path, it will look like a slight slope that gradually decreases downward as the distance increases (just like a football). The ultimate goal for a bullet is to maintain as much of its muzzle velocity as possible throughout its flight path. Every caliber has a different ability to fight gravity and air friction and stay airborne. Ballistics Coefficient (abbreviated “BC”) is a bullet’s ability to resist air friction and stay airborne. A high number means the bullet is more efficient at resisting air friction (negative acceleration). A high number also means that the bullet will retain MORE velocity as it moves down range.  Basically, BC is a measure of how Aerodynamic a bullet is. It is important to note that BC is merely a measure of a bullet’s ability to resist air friction. A high BC is NOT an indicator of how “good”  a round is.

Figure B2

Bullet trajectory of a .223 Remington (AR-15 bullet) out to 200 yards. NOTE. Bullet DOES NOT travel in a straight line.

Figure B3

.40 S&W (180 gr) on Left and .50BMG (750 gr) on right. Can you guess which round has a higher BC? If you guessed the one on the right you are correct. Just look at the shapes. Which one looks more aerodynamic? The .40 S&W has a BC of .164. The .50 BMG has a BC of 1.050. According to these numbers the .50 BMG is nearly 10 times as efficient as resiting air friction than the .40 S&W. Source http://www.hornady.com/store/50-BMG-750-gr-A-MAX-Match/

Bullet Drop

An important subset of External ballistics measures bullet trajectory-Bullet Drop. Simply put, “Bullet Drop” is a set of figures, either expressed in a line graph or a numerical chart, that illustrates the effect that gravity has on a particular bullet at various ranges. You may hear an experienced shooter compliment a round a say it shoots “flat”.  “Flat” simply means that the bullet has an efficient trajectory and resists gravity and air effectively.  Bullet drop charts are especially important for hunters, competitive shooters, and police/military snipers. For instance, a .300 Winchester Magnum may shoot “flat” out to 320 yards. This 320 yard distance is called “Point Blank Range”. Point blank range is the MAXIMUM “can’t miss distance” for a particular round. Beyond 320 yards, this round may start to “drop” (For instance the drop rate may be -6 inches at 600 yards). To compensate for this, an experienced shooter will have to aim HIGHER than the intended impact point in order for the bullet to hit on the desired location. Every bullet has its own unique drop rate. These unique drop rates are also influenced by humidity, wind, elevation, barrel length, bullet weight and bullet composition.

Fig B4

Bullet drop chart for common large game hunting cartridges. “300”, “600” etc indicate distance. -1.1, -7.5 etc indicate bullet drop rate at a particular distance. Question. What is the bullet drop rate for the 338 Lapua at 900 yards? The correct answer is -20.8 inches. This means in order to hit the desired target, the shooter needs to aim at least 20.8 inches HIGH. If the shooter doesn’t aim high enough, the round will simply bury itself in the dirt. (Just like a quarterback needing to LOB a football 60 yrds instead of throwing it straight).

Terminal Ballistics

Terminal ballistics is the study of how a bullet behaves when it impacts its target. Velocity, bullet type (soft point, hollow point, rifle, flat point, round nose), and target type all play important factors in terminal ballistics of a round. This is an EXTREMELY broad subject. For our purposes we will focus on basic characteristics of common rounds and how they behave. Panthera Armory believes in the utilization of visual observation as a learning tool. Ever heard of “ballistics gel tests”? These tests, even though they can be flawed, vividly illustrate how rounds behave when they hit soft tissue.

Video B1

This is how an Full Metal Jacket .45ACP behaves. The blunt shape of this round makes it go “through and through”.

Video B2

This is how the AR-15 bullet behaves. Notice how the round tumbles. This is called the “Yaw” effect. Other experts call it the “boomerang effect”. This is common among rifle rounds because of their high velocity. The yaw effect is responsible for causing massive trauma to surrounding tissues. This is how such a small rifle round such as the 5.56 can cause impressive terminal ballistics.

If you need further research on TERMINAL Ballistics Check out Brass Fetcher on youtube. By far the BEST slow motion close up Ballistic gelatin tests on youtube. You see the bullets deform and the gel oscillate from the kinetic energy transfer.

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What is “caliber”? What is it a measure of?

“Whats a bigger caliber .40 or .380?” “Whats the difference between a 9mm and a .357?” “What does {caliber} mean?”

Caliber is basically the measure of the diameter of the projectile being fired. It is also a direct measurement of the diameter of the bore of a particular firearm. This measure can either be in fraction of an inch (i.e. .380) OR in millimeters (i.e. 9mm).

Common handgun calibers comparison

One common thing to remember in regards to caliber is that SOME calibers are not EXACT measurements. For instance, the .44 Remington magnum is NOT exactly .44 of an inch. It is closer to .429 of an inch than .44 of an inch. Another thing to remember about calibers is that we commonly see SAME caliber bullets stuffed in different size casings. For example, take a look at the figure above. If you did a little math, you will see that the .357 and the 9mm are the same diameter. The .40 S&W and the 10mm are also the same diameter. Let’s observe how this looks in a rifle example.

From left to right .308 Winchester, 30-06 Springfield, .300 Winchester Magnum (Missing is the Winchester 30-30, and the 300 Remington Ultra magnum)

These 5 cartridges are all in the “30 caliber family”. The projectile of ALL 5 of these cartridges measure’s .308 of an inch. These are essentially THE same SLUG stuffed in a different casing. “So which one is more powerful?” Take a wild guess between the 3 in the photo as to which one is more powerful. If you picked the one on the far right, you are correct. GENERAL RULE OF THUMB. Look at the size of the casing. The LARGER the casing, THE MORE gunpowder its going to hold. The MORE GUN POWDER the casing holds the faster the bullet is going to travel. The faster that bullet travels the more kinetic energy its going to have etc..

GRAIN-The STANDARD unit of Bullet weight measurement

You may hear or read of different bullets being 200 grains (often abbreviated “gr”), or 180 gr. This is the WEIGHT of the bullet/slug/projectile. For example, The .40 S&W is available in 135 gr, 155gr, 165 gr and 180 gr. Lets ask ourselves a few common sense questions and establish a few GENERAL ground rules (there are a few exceptions with high performance ammo manufacturers) 1. The LIGHTER the projectile, the higher the velocity (bullet will move faster through the air) but will not penetrate as deeply as a heavier projectile. 2. The HEAVIER the projectile the slower it will travel, but will work wonders when it comes to penetrating surfaces and retaining momentum. SOO..if you had a .40 S&W pistol with FMJ’s and you wanted to PUNCH THROUGH A WINDSHIELD (or sheet rock, or sheet metal, or plywood) and knock out a target in the front seat, which weight would you use? 135 gr or 180 gr? The 180 gr choice would be more practical. The slower moving 180 gr will retain MUCH more of its kinetic energy than the much FASTER moving 165 gr.

“Sooo…since a 230 gr .45ACP is a bigger bullet than the .357 Magnum which weighs 158 gr, is it more powerful?” The Answer is NO. Take a look at the figure below. 

.357 S&W Magnum (158 gr) on left .380 ACP (95 gr) in middle and .45 ACP (230gr) on right.

Obviously the .45ACP bullet diameter is wider than the .357 magnum. The .45 ACP also weighs more. SO…which one generates more power? To answer this question, Remember the GENERAL rule of thumb we previously discussed. That .357 magnum has a LOT more powder in its casing. This allows the .357’s 158 gr projectile to travel a LOT faster than the 230 gr .45 ACP. This considerable advantage in velocity allows the .357 to generate over TWICE the energy of the LARGER .45 ACP. GENERAL RULE OF THUMB…A LARGER DIAMETER CALIBER IS [NOT] ALWAYS MORE POWERFUL.

 

Should I be concerned about the capacity of my handgun?…

“What is the importance of capacity?” “Do I really NEED 15+1?” “Does it really take an entire magazine to eliminate a threat?” These are questions to ask yourself BEFORE you make a financial commitment to a conceal carry handgun. Some gun owners advocate carrying the maximum amount allowed by comfort. While some gun owners sacrifice a high capacity magazine for the sake of an easier concealment. To be frank, its not going to take 15 rounds to neutralize your typical threat (unless the suspect is on bath salts, PCP, or has a metal endoskeleton). HOWEVER high capacity magazines DO play a critical role. Lets look a this scenario.

The Great X Factor…Multiple Assailants

Man pulls into his garage with his family. As his automatic garage door closes, one suspect grabs the bottom of the garage door and holds it. This allows his armed companion to slide under the door to proceed to assault the driver. As the suspect opens the driver’s door, he his showered with 3-4 shots to the torso and flees out of the garage.  The driver pursues the assailant that was holding his garage door and donates a pair of shots to him and then delivers 3 more shots to another accomplice. I counted approximately 10 or 11 shots. (Watch closely and tell me if my math is off).

What if the property owner had a Subcompact conceal carry weapon like the Glock 42, Or the Glock 27, or the Smith & Wesson Bodyguard? All of these are VERY popular conceal carry weapons that typically have a magazine capacity of less than 10 rounds. If he had been carrying one of these low capacity weapons and encountered multiple  DETERMINED attackers…he and his family in the vehicle would have been in serious danger. Compact or full size pistols will typically offer well over 10 rounds while still being highly maneuverable.  Its not barbaric. Its just a case of “You’d rather have it and not need it…than need it and not have it”.  Just remember..if you choose a lower capacity weapon (less than 10 rounds)…be ready to flee if necessary. It may be difficult to hold your ground against multiple assailants.

What factors are to be considered when concealed carrying?

Shootability

“Can I control this gun?” “Can I thread the needle with it?” “Is this handle too small?” “Is this too much recoil?” These are key questions to ask yourself BEFORE purchasing a handgun for conceal carry. A person that decides to conceal carry is doing so because of personal protection. Buying a gun that is cosmetically appealing is NOT as important as getting one that you can control and shoot accurately. Think of them like cars. You may WANT that Ford Excursion because your friend has one and its pretty. But you may not be able to AFFORD weekly fuel costs, maintenance, and tires. You may find the Excursion extremely hard to parallel park and control while on the freeway. So is the Excursion actually for you? Maybe you should go with the Ford Fusion or the Taurus. Going to a gun range and trying rentals is a GREAT idea to familiarize yourself with different handguns. IF you are investing in personal or home defense you NEED to be able to comfortably shoot your handgun AND be able to place shots where you need them to go.

Concealability

“Is this gun bulging out of my pants?” “Can I do an appendix carry?” “Can I carry on my hip?” “Can I carry on my back (6’o clock)?” “Would I have to carry this gun inside my waistband (IWB) or Outside the waistband (OWB)?” These are questions to ask yourself BEFORE purchasing a handgun for conceal carry. CONCEAL CARRY IS NOT CONCEAL CARRY IF YOUR GUN IS TOO FRIKKIN BIG!!! IF YOUR GUN IS BULGING OUT OF YOUR GARMENTS..ITS NOT CONCEAL CARRY ANYMORE!!! Rentals at a gun range will give you a perfect opportunity to see how this gun feels on/in your waistline. Holsters will provide extra security, stability and comfortability to your conceal carry firearm. Observe yourself in the mirror with your gun in your waist to see if it bulges or imprints itself.

Comfortability

“Is this gun too heavy?” “Does it make my pants sag?” “Can I sit down with it comfortably without re adjusting it?” Comfortability will be a crucial deciding factor while conceal carrying. IF YOUR GUN IS NOT COMFORTABLE (WHILE STANDING AND SEATED) OR TOO HEAVY, YOU WILL BE A LOT LESS LIKELY TO WANT TO CARRY IT. Again, Rental guns will provide a great opportunity to examine a gun’s comfort for conceal carry.

Extractability

“Can I extract my weapon with one hand?” “Can I extract my gun CONSISTENTLY  with one EFFICIENT/SWIFT MOTION and acquire a target without getting my garments caught in the way?” Ok..lets say your conceal carry gun is accurate, the perfect size for you, perfect weight, is extremely comfortable, and amazingly concealable…but you have trouble throwing that covering garment out of the way to extract and aim down range…This will take practice. If you EVER have to draw…it will need to be SWIFT…and EFFICIENT with as few motions as possible (For example…an attack by a dog will command the use of a ONE handed extraction). PRACTICE ON YOUR EXTRACTIONS WITH AN EMPTY CHAMBER.

User Friendliness

 “Does this gun have too many knobs?” “Is this gun easy to breakdown”? “Is this gun easy to clean?” Ask yourself these questions before you get your gun. Gun rentals are an easy opportunity to evaluate user friendliness. If a gun is user friendly (like Sig Sauers, Glocks, SD’s and SW’s) you will be more likely to disassemble it and clean it. Regular disassembly and cleaning will virtually guarantee 100% functionality. If you are conceal carrying, this is critical. A failure with your weapon during a self defense response will lead to disaster.