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Miscellaneous Questions #1What
happens when a bullet is fired straight up? Q. What happens when a bullet is fired straight up? A. A lot of shooters have wondered what happens when a bullet is fired vertically. Popular lore includes such mis-ideas as the bullet burns up falling back down, it comes down at the same velocity as its original muzzle velocity, and probably one that says it disappears in a time warp. The two best references on the subject are "Hatcher's Notebook", (by Julian S. Hatcher, 3rd edition, June 1962, Stackpole Books, ISBN: 0811707954) which includes a chapter on bullets fired vertically, and an article titled "Terminal Velocity and Penetration Studies," by Lucien C. Haag, which appeared in Vol 2, No. 1 of Wound Ballistics Review. This information is excerpted from both. First, it must be understood that recovering vertically fired bullets is difficult because wind causes them to drift from the expected vertical line. (This probably accounts for many of the myths.) Hatcher's tests indicated that on the average, vertically fired rifle bullets reach about 9000 feet in altitude (slowed from their muzzle velocity by air drag and gravity to zero velocity), taking about 20 seconds to reach maximum height. Then, pulled by gravity, and slowed by air drag they take about 40 or so seconds to return. Bullets fired vertically come back base first. Why? Read on! Hatcher describes one experiment with the 150gr M2 Ball bullet fired vertically. When it came back from vertical (round trip time was about 42.9 seconds) it left only a 1/16 inch dent in a soft pine board that it happened to hit. (Not exactly what it would do at 2700f/s, eh?) Based upon this and similar tests Hatcher concluded that the impact velocity was about 300 f/s, which from additional testing appears to be the terminal velocity (the maximum free fall velocity which is limited by air drag on the body in question) of that bullet falling from any height in the atmosphere. (If I remember correctly from my limited parachuting experience the terminal velocity of a falling person is somewhere around 130 mph or about 200 f/s.) What does not substantially change, even at extreme range, is the rotational speed of the bullet that was imparted by the rifling (around 300k rpm) since the effect of air drag on the rotational velocity in negligible. Thus the gyroscopic action, once the projectile is stabilized, tends to keep the bullet oriented in the same direction, thus the base first (well ok, original position trailing end) return. It is interesting that this was not commonly known until just before WWII. The British had lots of dud antiaircraft rounds that all came back base down, or more correctly oriented to the same elevation as shot from the gun. BTW, this is what raises hob with traditional long range small arms ballistics. With lots of elevation on the bore (past 2,000+ or so yards) at the far end many bullet are actually falling sideways and all frontal air drag algorithms are out the window. Interestingly, Hatcher describes an experiment that shows the gyroscopic stability at work. They loaded the 150gr M2 flat based bullet backwards and found that the round trip time was a bit shorter (about 30.4 seconds) due to the bullet being "streamlined (point down) on the return trip. The drag on the upward trip was not as greatly effected due to the high muzzle velocity. No estimated impact velocity was given but it probably would have been somewhat higher due to the lower air drag on the bullet since it was coming down point first. The Haag article used a ballistics computation program to calculate vertically fired bullet performance and came up with results comparable with Hatcher's work. Using bullets ranging from the .22 rim fire to the 180gr .30 caliber spitzer in the .30-06 the time of flight (up & back) ranged from a low of 25 seconds for the .25ACP to a long of 77 seconds for the M193 ball. Maximum altitudes ranged from a low of 2288 feet for the .25ACP to a high of 10,103 feet for the 180gr .30-06. Terminal velocities ranged from 134 f/s for a tumbling .22 Short to a high of 323 f/s for the 180gr .30-06. Haag calculated the performance of the .30cal 150gr M2 ball round fired by Hatcher as a maximum altitude of 9330 feet and a round trip time of 57 seconds which is, for all intents and purposes, the same as Hatcher's observations. As a point of interest, a velocity of about between 180 and 360 f/s (±) is needed to penetrate skin. The wide range comes from the non-uniform strength of normal skin tissue. Projectile shape has no statistically significant effect on the penetration. However, one could still be seriously injured if struck by a falling bullet even if it doesn't break the skin. Those interested in learning more about vertically fired bullets may want to obtain a copies of Hatcher's Notebook and the Haag article. Q. What is the most powerful handgun? A. That can be a sticky question. For production handgun cartridges the winner used to be the .44 Magnum which can throw a 240gr bullet at over 1400 f/s from a seven to eight inch barrel. Recently the .454 Casull, the .475 Linebaugh, the .460 S&W, and the .50 S&W became production rounds. The .454 throws a 300gr bullet at 1650. The .475 will boost a 400 gr bullet to 1300 f/s, the .460 a 300 gr to about 2000, and the .50 S&W will get a 350 gr bullet to 1900 f/s. Any of these will give you your recoil "jollies." (I've fired all of these and the .460 S&W is by far the worst in my opinion.) In the custom field, the all time winners are probably the Triple-Action "Thunderer" and Maadi-Griffin bolt action pistols in .50 BMG(!!!) and some similar crew served "pistols" from other manufacturers. These "pistols" have barrels of about 12" -15" in length, weigh between 10 and 17 pounds, and depending on barrel length are about 2 feet long. The barrels are fitted with massive muzzle brakes, not only to help control the recoil but to also prevent the shooter from being singed by the muzzle flash. Recoil is described as "manageable." I have viewed a video of a .50 BMG Thunderer "pistol" being fired and the muzzle flash is best described as "interesting." If you are within 5 feet of the sides or front of the muzzle you are a fire risk! Chronograph data suggests that with that the M33 Ball cartridge which is listed as firing a bullet with a nominal weight of about 660 gr at a nominal 2910 f/s from a 36" barrel. one will get velocities between 2200-2300 f/s from these pistols. If we discount the effect of the muzzle brake, the free recoil energy of this pistol (assuming 15 pounds weight and 2300 f/s muzzle velocity) would be about 167 ft lb, and it would generate about 7700 ft lb of muzzle energy. At last! A pistol for elephant hunting! There is at least one handgun made in both .458 Win and .600 NE (that's a 900 gr bullet at about 1900 f/s from a rifle) by Pfeifer Waffen in Austria. It is a 5 shot single action design that weighs 13.2 pounds with a 13" barrel. In .600 it gives 1515 f/s and 4600 ft lb. The .45-70 cartridge has also been chambered in some handguns. A correspondent recently informed me that from a 14" .45-70 Contender he gets almost 2000f/s and 2600 ft lb with a 300gr bullet and about 1600f/s and 2000 ft lb with a 350gr bullet. (He didn't indicate if he still has any feeling in his shooting hand.) My other choice for a "big" pistol would be the British "Howdah" pistols which were basically a .577 Snyder double rifle with the barrel cut off to seven inches and a pistolgrip stock. They were designed to shoot a attacking tiger off the back of the elephant you were riding through the jungle. Legend has it that the way you employed it was to hand it to the tiger and let him fire it! (Consider that the .577 launches a 480gr bullet on top of 70+ gr of black powder for probably about 1000 f/s in the short barrel--in a three pound pistol, and with its tendency to "double" it was truly a pistol for the "manly man.") Q. Shouldn't I always use boat tailed bullets so I get a flatter trajectory? A. Yes, boat tailed bullets do help you to get a flatter trajectory. However, the effect is only really meaningful at very long ranges. (Since 95% of all shooters--some gun-rag writers excepted--have trouble seeing, let alone hitting, anything past about 300 yards BT bullets have little practical effect.) The chart below shows the trajectory of two commercial 165gr bullets from the same manufacturer. They are identical except for the fact that one is flat based and the other has a boat tail. The chart is based upon a 225 yard zero, a 1.5" sight height, and a muzzle velocity of 2700 f/s. Something else to keep in mind--while boat tail bullets tend (as a generalization, mainly in large bore rifles, i.e.: .30 cal) to be capable of better accuracy than flat based bullets many rifles do not handle them well and you may get your best accuracy with a flat based bullet. Especially in small calibers flat base bullets tend to give lower velocity standard deviation than boat tails. Use the bullet style that gives you the best accuracy and don't worry about little differences in trajectory.
Q. What is the maximum range of my (user supplied caliber)? A. First we have to determine just what we mean by "maximum" range. "Absolute maximum range" or the farthest distance a given bullet will travel is one thing. "Maximum effective range" or the distance a given weapon system can be effectively employed by a user under most conditions to provide the desired results is another thing all together. Maximum
Range In a vacuum a firearm would achieve its absolute maximum range at an elevation of 45°. However, with typical small arms projectiles the effect of air resistance is so great that maximum range is usually obtained at a departure angle of between 29° and 35°. The table below gives the calculated approximate absolute maximum ranges for some common rounds using modern drag modeling techniques at standard sea level conditions, and a not so common projectile. It may differ from some previously published data based on older methods of computation. The data indicated by "#" is from government firing tables. Note that all this data assumes point forward flight during the entire trajectory and is based upon "standard" conditions. However, this may in fact not be the case--see the article on vertically fired projectiles, above--except for the M829 "dart" which is fin stabilized. While this data is sound one should not consider the data to hold for all cases and conditions--especially when considering range safety implications. Changes in projectile stability, elevation above sea level, temperature, barometric pressure, humidity, and wind speed and direction at both ground level and at altitude can contribute to wide variances (15% or more).
For round shot pellets, the maximum range in yards as stated by Journee's Rule is approximately 2200 times diameter of the shot in inches for typical shotgun velocities. Velocity is not considered in this formula because at typical shotgun velocities the drag is fairly consistent. The rule holds fairly well when compared to actual firing tests giving shorter ranges for small shot sizes and longer ranges for buck shot.
Absolute
Maximum Range In the graphic below the projectile has a level ground maximum rage of 5084 yards. However, if fired from an aircraft flying at some 27,000 feet the bullet would reach vertical free fall after traveling 6180 yards, dropping 321316 inches (8925 yards) below the line of sight. ![]() Effective
Range The amount of power needed to be "effective" on a given target is a difficult thing to quantify. Kinetic energy is not a good indicator of target "effect" for soft targets--the actual damage being done to tissue is more important. However, for the want of something better military statistics call for the delivery of between 35 to about 270 ft/lbs of energy to the target to be "effective. The wide range is indicative of the difference in specifications and ideas of the subject. For the purpose of further discussion lets simply ignore the power question, whose discussion belongs in the terminal ballistics area, and look at the firearm/shooter equation. First let's assume a target size of 18" width. For that we need a maximum mechanical accuracy that will guarantee that a bullet will stay within that zone. For a rifle/ammunition combination that could deliver every shot inside of 1.5 moa (minutes of angle) the maximum mechanical effective rage would be 1200 yards on that 18" target. (A minute of angle being effectively 1" per 100 yards of range.) However, that is just the gun. We now have to consider the shooter. Most individuals can just barely discern an 18" target at 600 yard with the naked eye and if they know where the target is maybe about 900 yards with an optical sight of moderate power (3x - 6x). (I am avoiding specialized high power target type optics since we are talking field use here.) Ok, now we're down to somewhere between 600 and 900 yards. That's still pretty impressive, eh? We also have to bring the shooter's skill into play. Most decent shooters can, on a good day under field conditions, keep all their shots from a 1.5 moa rifle in a 4 to 6 moa group. (We are exempting the long range target shooters and specialists, whose shooting skills are far above the general population, from this discussion.) Some can do better; many do much worse. With an 18" target that means an maximum range of between 300 and 450 yards (6 moa @ 300 yards = 18"; 4 moa @ 450 yards = 18") Another concern is the trajectory of the bullet being used. Once the bullet's trajectory begins to curve steeply downward (normally after about 300yards or so) estimation of drop can get tricky and can make hitting a target difficult unless one knows the bullet's trajectory well--which most people don't. This also puts a 300-400 yard damper on things. (We are assuming--boy I hate that word--a proper field zero of around 225 yards or so here. See the external ballistics page for an in depth discussion.) Interestingly, the US Military manual for the M14 rifle gives the "effective" range as 460 meters and the absolute maximum as 3720 meters so it looks like we are in the ball park. Note that they define "effective range" as "the greatest distance at which a weapon may be expected to fire accurately enough to inflict casualties or damage." (Italics mine and they are simply expecting to hit a humanoid sized target anywhere.) However, there is still another fly in the ointment. We have been talking about hitting any where on an 18" target. The kill zone of most game animals runs between 6 and 12" in diameter. Uh oh! Let's see now, if we split the difference and say a 9" kill zone: 6moa @ 150 yards = 9" and 4moa @ 225 yards = 9" which puts the average good shot's effective range at between 150 and 225 yards. Gee! Those gun writers routinely pop 'em at 500 and 600 yards, don't they? Tests conduct by the military have shown that the average rifleman armed with either the M14 or M16 has about a 10% chance of securing a first round hit on a target 300 yards away. And there is still another fly in the ointment. Tests conducted by the US military showed just how difficult it is to even see targets in the field, and if you can't see them how can you hit them. The chart below shows the likelihood of seeing a standing humanoid target as a function of range under field conditions. It is based upon data developed by the Army Operations Research Office during project SALVO.
As a good friend once said, shooters are surpassed only by fisherman in statistics. I have been present when a lot of so-called expert shots were given the chance to hit a target way out there under field conditions and very, very, very few could actually do it let alone see the target.. I've seen many shooters who couldn't even make 75 yard field shots consistently with their razzle-dazzle magnums--even from a bench! Few people have any idea of just how far away 400 - 500 yards is. Try this. Find a BIG clear field or a long straight road. Have someone stand somewhere and then measure or pace off an honest 400 - 500 yards. Turn around and see just how far away they are. Or on a long straight road set your odometer to 0 and then drive. Every 1/10 mile is 176 yards so drive 4/10 or 5/10 of a mile and then look behind you. Fr. Frog's Rule of the Field 1.
Shooters are exceeded in their bragging about distant
shots only
by fisherman and the size of the fish that got away. Now I'm sure that this is going to ruffle some feathers but that's tough. Maybe you can do it every time, and if you can congratulations--but I'd have to see it to believe it. When you can hit a 10" target at 300 yards with your first shot (no sighters--no warm ups) and four following shots from a field position then you have arrived. Until then, don't deceive yourself. For the rest of us, what can we do to improve our effective range? Practice! Go to a good shooting school that teaches practical field riflery and the use of the sling. Learn your rifle and its ammunition, stay away from the shooting bench, and practice, practice, practice. And, should you ever take a game animal at greater than 300 yards you should write yourself a letter explaining why you had to do so at such a range. Note that the 120mm M829 "dart" round in the table above has a stated maximum effective range in the M1A2 Abrams tank gun system of 3200 yards, although kills have been recorded at out to 6500 yards (where the typical group size is about 5 ft in diameter). Now, as an historical foot, note the table below lists the effective ranges and maximum ranges of some common weapons from history.
Q. Why do some guns of the same caliber seem to kick harder than others? A. The perception of recoil is a very personal thing. While the "statistical" recoil of a firearm can be calculated mathematically fairly easily, and is the same for a given gun weight, bullet weight, powder charge, and velocity, the shooter's perceived recoil is effected by several things: Tightness with which the firearm is held. If the firearm is not tightly held the firearm gets a "running start" and smacks the shooter harder. Anyone who has had a bad mount with a rifle or shotgun probably has had the black and blue mark to prove this. With a firm grip the shooter's body mass dampens the firearm's motion and the perceived recoil is less. If a rifle's stock has a lot of drop or if a pistol's barrel is high above the line of the arm the torque effect is much more pronounced and the firearm rises more, increasing the perceived recoil. This effect is often commented upon by people who have shot both the Browning P35 and a SIG 9mm side by side. The SIG's higher bore axis gives the perception of greater recoil. Narrow, or sharp edged butt plates or pistol grips concentrate the recoil energy in a smaller area thus magnifying the effect to the shooter. Lighter firearms, having less mass, have a higher recoil velocity which accentuates the perceived recoil due to the sharpness of the blow. With two rifles of the same recoil energy but having different weights, the lighter one will have a higher recoil velocity and will feel as if it kicks harder or at least kicks "differently." A very slightly built shooter may experience more perceived recoil since they have less body mass to act as a damper. If the shooter is afraid of or worried about recoil then they may in fact have more of an "experience" than someone whose mind is on other things. There is a story told about the great African hunter Selous who once had his 8 bore double rifle "double" on him. (We're talking about two 1250 gr bullets backed by up to 14 drams (350gr !!!!) of black powder for about 1500 f/s, from a 16 pound or so rifle!) When asked what the recoil was like he remarked that he hadn't noticed it! I've often wondered just what it was that he was facing at the time or if he had simply had his brain scrambled by the recoil. One of the above rounds would generate over 130 ft lb of recoil in that rifle! (As a comparison, the .458 Winchester generates about 55 ft lb of recoil in a 9½ pound rifle.) With both barrels fired at the same time the combined effect of a 2500 gr bullet at 1500 f/s would generate some 500(!!) foot pounds of recoil energy in that rifle As a further corroboration of the mental effects of recoil I have on occasion, during training former non-shooters with standard or reduced loads, snuck in a full house load once the shooter has stopped worrying about recoil. After the "bang" the comment is generally "That one seemed louder than the rest," and so far I've have never had anyone complain about the increased recoil. If you would like to calculate recoil energy or velocity the following formulas will be of interest. WG = Weight of gun in pounds Notes: The "4000" is the nominal velocity of the powder gases at the muzzle for commercial smokeless powder and the observed range is between 3700 and 4300 f/s. It is sometimes stated as 4700 in some sources but this is based on observations of artillery, not small arms. You can try it with both values to see the effect of the different numbers. If you are doing these calculations for a black powder load use 2000. Q. What about muzzle brakes? (In relation to recoil.) A. A properly designed muzzle brake can have a noticeable effect on recoil and muzzle climb. However, note that most "muzzle brakes" are designed to help control muzzle climb rather than rearward recoil. Some designs attach to the barrel and others are actually part of the barrel. There are some very efficient designs available that do have a fairly dramatic effect on recoil, but they won't turn your "super-magnum" into a .22 recoil wise. Muzzle brakes work diverting some of the energy of the expanding powder gases to the side and rear rather than letting it just blast forward thus reducing the gases rearward "thrust" and many designs divert some of the gas upward to counteract the natural muzzle rise. The big disadvantage of such recoil reducing muzzle brakes is that they tend to dramatically increase muzzle blast to the rear and side of the firearm. When shot from a bench at the range you may blow your neighbor's ammo and accessories right off of his bench and in the field they can damage the hearing of anyone next to you. A friend's short-barreled Barrett .50 BMG "CQB" rifle has a massive muzzle brake and recoils like a heavy 12 ga. However, he has cracked the windows of a truck parked 15 feet away with the muzzle blast. While it is possible to design a muzzle brake that will not increase blast such a design is very tricky, not to mention that the BATF considers anything that reduces muzzle blast more than 2 dB from a bare muzzle a "silencer" which gets you into all kinds of trouble. You should also be aware of the fact that muzzle brakes work most efficiently on high intensity rounds in which the muzzle pressure levels are high and are much less efficient on moderate rounds (which don't need them anyway), and of the fact that an improperly installed muzzle brake can adversely affect accuracy. Generally, unless you are very sensitive to recoil or are shooting a very powerful and light weight firearm you should probably not waste your money on them for manually operated firearms. (I'm sure some muzzle brake manufacturers will disagree with me on this point.) However, I will gladly admit that a well designed one can be handy on semi-auto and full-auto rifles as they can reduce muzzle climb significantly during rapid fire. Note that many "muzzle brakes" also function as a flash reducer and many "flash hiders" also do double duty as a muzzle brake. Q. Is blank ammunition really dangerous? A. Absolutely! First, let's reiterate the second rule of firearm safety. Never point a firearm at anything you are not willing to destroy. Now say it again: Never point a firearm at anything you are not willing to destroy. Blank ammunition, while it contains no bullet in the usual sense does project bits of wadding material (some of which are fairly thick) and powder, as well as a blast of high pressure and very hot gases which can penetrate skin at a fairly great distance. Common smokeless powders have an energy potential of around 180 ft lb per grain weight of powder. Using GI .30-06 blanks I was able to punch holes in a cardboard target at 7 feet quite regularly and at near contact distances I could easily break a 1" board with the muzzle blast. Using .38SPL blanks I could shatter a watermelon at 2 feet and pepper its skin at 5 feet. Note that some military ammunition sold as blank ammunition and which is totally made of plastic with a metallic base is actually short range practice ammunition that fires a hollow plastic "bullet" at very high velocity. Nuff said! Remember, Never point a firearm at anything you are not willing to destroy. Also, keep in mind that the muzzle blast from a blank (just as with live ammunition) can damage your hearing. Q. What do the various bullet tip colors on military ammunition mean? A. Different countries have utilized different color codes for different ammo types. Current US color codes and identification markings for small arms ammunition are as follows. The data below is as of 2013, courtesy Lake City Army Ammunition Plant and others, and includes some limited issue and experimental ammunition. If you know of any others please contact me by clicking here.
Thanks to Ed Lay for the info on the 5.56 mm API and Dan Watters for info on other limited production 5.56 mm rounds.
Q. What are some common conversion factors for shooting related measurements? A. See table below.
* NOTE: You should be aware of the fact that the "dram equivalent" measurement used with shotgun shells relates the performance of the load to an equivalent dram weight charge of black powder. It does not relate to the actual weight of the smokeless powder charge so don't develop loads based on these conversions. Abbreviations There seems to be a random use of abbreviations. The following are the correct usage.
Note: The "fps" designation for feet per second has been replaced by "fs" to conform with the international abbreviation standards. For area or volume measurements simply use the "squared" or "cubed" superscript with the abbreviation as in 15 ft² or 25.2 cm³. By the way, when you abbreviate a measurement, the grammatically correct way to use an abbreviation is to use lower case for all units except those named for a person (V = volt, Pa = Pascal) and to have a space between the number and the abbreviation as if you wrote the units out, as in 20 mm (20 millimeter) and not 20mm. Do not add an "s" to pluralize. However, if decimal units quantifiers greater than 1.0 are used (in particular like deca-, centa-, kilo-, mega-, etc) they always have uppercase abbreviations, with the exception of "kilo" units where the "k' is lower case. Quantifiers less than 1.0 (deci-, centi-, milli-, micro-, etc) all have lowercase abbreviations.
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