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Bourjaily: A Shotgun Myth

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April 07, 2009

Bourjaily: A Shotgun Myth

By Phil Bourjaily

One of shotgunning’s enduring myths is that if you keep the barrel moving, you’ll sling the shot in an elongated pattern, thus helping you hit targets you would otherwise miss by overleading. You hear this theory expounded all the time, even from some very experienced shooters. “Just keep swinging and shoot way out in front of them. Your pattern strings out so far at 40 yards that the bird flies into the shot,” is how I heard someone explain it yet again last week. This concept is wrong on so many levels it’s hard to decide where to start debunking.

Yes, your pattern does string out, but it doesn’t hang in front of the target like a stationary lead curtain for the bird to crash into. It’s moving very quickly. At 40 yards a 10 foot shotstring passes a given point in .016 seconds, which is enough time for a target going 40 mph to travel only about four inches. It’s the pattern’s width, not its length, that gives you a margin for error if you’re slightly too far ahead of the target.

No matter how fast you swing your gun, you can’t lengthen that shot string by “slinging shot.” A shot charge is effectively a solid slug of pellets tucked inside the wad until it exits the muzzle and encounters air resistance. No matter how hard you swing the barrel, you can’t spread that shot sideways as if you were Angelina Jolie in "Wanted." Prove this to yourself by shooting at the surface of the water, or a very wide piece of paper. Move the gun as fast as you can, but the resulting pattern will still be round.

Nevertheless, this myth won’t die, in part because it encourages you to do the right thing – keep the gun moving – albeit for the wrong reason.

Comments (42)

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from Mike Diehl wrote 5 years 2 weeks ago

How about we all trust the physics on this and NOT shoot at the "surface of the water."

+3 Good Comment? | | Report
from NolanOsborne wrote 5 years 2 weeks ago

Good one Diehl!
while new to this.. i still admit that i beleived the shot pattern "slung abit"

+2 Good Comment? | | Report
from MLH wrote 5 years 2 weeks ago

I have seen high speed camera shots that show the shot string to be more 3D than I originally thought. But, with the velocities involved, I agree with you. We just can't move the barrel fast enough to string the pattern.

But I wonder if it helps some shooters to psych themselves into thinking that they are stringing the pattern along. Might be for the wrong reasons but it might help them keep the barrel moving.

+2 Good Comment? | | Report
from Quiet Loner wrote 5 years 2 weeks ago

I saw an article in American Rifleman several years ago on this. Someone constructed a big plywood wall mounted on a truck side. To give an idea of the age of the research, I believe it was a Ford Model A truck. They then drove the truck at various speeds past a stationary mounted shotgun as it was fired. Don't know how much they paid the driver. No matter how fast the truck went, patterns remained round.

+3 Good Comment? | | Report
from Jeff Bowers wrote 5 years 2 weeks ago

Thank you. I know someone who voiced this theory many years ago. I did not know enough to either agree or disagree with him. Sometimes you get to feel if somebody's done more of a thing than you (like shotgunning), they must know what they're talking about.

That is, until you get somewhere like here.

+2 Good Comment? | | Report
from focusfront wrote 5 years 2 weeks ago

The pattern will remain round no matter how fast you swing the barrel because the shot comes out of the barrel more or less as a unit. Only after leaving the barrel does it spread out.

That 'slinging shot' routine might be a good idea for the wrong reason, however. All us old rifle shooters want to aim the shotgun rather than point and swing it, and it goes against the grain for us to follow through with our swing after we pull the trigger. Slinging shot is a ballistic fallacy, but the idea that you are slinging shot might create a mindset that promotes swing and follow through. Which promotes hits. What do you think?

+2 Good Comment? | | Report
from buckhunter wrote 5 years 2 weeks ago

Thanks Phil. Maybe you can give some shooting advice to Michigan State. After lastnight it looks like they've been getting bad advice.

+2 Good Comment? | | Report
from Ralph the Rifleman wrote 5 years 2 weeks ago

This was target practice for WWII airplane machine gunners;man rode on a 1/2 rail car trailer while moving objects were tossed at them. Some of the "shotguns" looked like browning machine guns, too!

+2 Good Comment? | | Report
from WA Mtnhunter wrote 5 years 2 weeks ago

If an object moves at 40 mph, that is 5280 ft x 40 = 211,200 feet per hour. That is 3520 feet per minute and 58.66 feet (704 inches) per second or .05866 feet (.704 inch) in one one-thousandth of a second. So, in .016 seconds, a 40 mph duck moves 11.2 inches vice 4 inches.

Can you advise if my math is flawed?

+2 Good Comment? | | Report
from Mark-1 wrote 5 years 2 weeks ago

I can agree with the physics of the shotstring vs the old myths.

Upon shouldering and shooting some of those very old shotguns I don’t know how people hit with them. The idea of keeping the swing going and “get way out front” makes sense when I consider the relatively slow lock and ignition times with these old guns.

I thought the old muzzleloading cap shotguns bad. Then I tried shooting clays with a flintlock shotgun. What a trip.

Those old shooters must have shot with their heads high. Stocks on those old doubles have too much drop for me. I’m always looking below the receiver into the tang when I shoulder them.

+2 Good Comment? | | Report
from Mark-1 wrote 5 years 2 weeks ago

WA,

Think you have the duck going the speed of the shot string in your calc's, not at 40 mph.

+2 Good Comment? | | Report
from Beekeeper wrote 5 years 2 weeks ago

Old ideas die a long and miserable death... We will forgive the physics lesson, just keep those barrels moving guys and gals!

+2 Good Comment? | | Report
from ishawooa wrote 5 years 2 weeks ago

It has always been my observation that my best shotgunning was performed using IC choke with the game within a reasonable distance due to the quicker and wider spread of the pattern.
This brings to mind another shotgun story. Once at a deep camp down south where shotguns only were allowed I overheard a younger hunter ask an older guy why it was not a good choice to use a full choke to shoot buckshot. The wily old fellow squinted his eyes and replied "If you use the tight choke the buckshot have to wait their turn to get out of the end of the barrel".

+2 Good Comment? | | Report
from HogBlog wrote 5 years 2 weeks ago

Can't say I've ever heard the shot stringing myth, but from some of the other shooting mythology, I can see how people would come up with it.

+2 Good Comment? | | Report
from ken.mcloud wrote 5 years 2 weeks ago

Wa mtnhunter is right.

a object moving at 40 mph travels 11.264 inches in .016 seconds.

No offense phil, but given this error I ran over the rest of your math, just to be sure.

It looks like you assumed the shot was moving at 625 ft/sec when 40 yds from the muzzle. When you assume a muzzle velocity of 1200 ft/sec that leads to an average deceleration of 135.89 G's.

That rate of deceleration seems way out of whack for anything but an impact shocks.

So, I whipped out Matlab and did a little non-linear dynamic simulation. I assumed you shot #8 lead shot at sea level with a muzzle velocity of 1200 ft/sec and a drag coefficient of .1 on each pellet. This ignores interactions between shot pellets but should get us in the ballpark.

This produced a shot velocity of 712.5 ft/sec at 40 yds downrange. So, I guess your estimate of 625 ft/sec was pretty reasonable.

(for those keeping score, Phil now is 1 for 2)

I then varied the drag coefficient from .1 to .4 (an acceptable range for a sphere). I got that at 40 yds the shot-string could be as spread out as 44 ft in the direction of the shot. I found this VERY surprising. I expected it to be much shorter.

So, again your estimate of 10 ft was at least in the right ballpark (or as us engineers say, on the right order of magnitude)

(Phil is now 2 for 3)

to wrap things up, I assumed a worst case shot-string length of 44 feet, and a shot velocity of 625 ft/sec. This would pass the duck in .0704 seconds. The 40 mph duck moves 4.13 feet during the time the shot is passing him.

(And the final score is 2 for 4!, about the same ratio as my NCAA bracket!)

So, after all that math we see that a large variation in the drag coefficient leads to a long shot-string which makes the duck easier to hit. (unfortunately this variation is essentially impossible to control and could be much smaller)

Since the length of the string at the muzzle is essentially zero, your swing will really not effect this length at all.

Conclusion: Phil is right, even if his math is a little off.

+2 Good Comment? | | Report
from Mark-1 wrote 5 years 2 weeks ago

Ooops. WA,

Your cacl's are within .66 ft of mine @ 40 mph. Not enough to make a squat of difference of what you figured that duck would move.

+1 Good Comment? | | Report
from Clay Cooper wrote 5 years 2 weeks ago

Reminds of the myth of the old Vietnam story about M16 bullets are designed to tumble instantly breaking the muzzle. First of all, if this was true then why does the M16 have rifling to begin with and if it did tumble the barrel is washed out requiring replacement.

The truth about this is, the M16A1 has a 1-14 twist for a 55 grain FMJ that is barely stabilized. Because the bullet is barely stabilized, the bullet instantly tumbles upon impact with devastating results!

+2 Good Comment? | | Report
from guncrazy74 wrote 5 years 2 weeks ago

I always flunked math but always get out and shoot as much as possible and I miss less. Good to know my priorities are straight.:)

+3 Good Comment? | | Report
from guncrazy74 wrote 5 years 2 weeks ago

Or as the old man says "Don't think, just shoot the damn thing!!"

+3 Good Comment? | | Report
from philbourjaily wrote 5 years 2 weeks ago

WAMtnhunter -- My math is backward. You convert MPH to FPS by multiplying by 88/60, except I always do 60/88 by mistake.
Ken McCloud -- Thanks for taking the time to rake my calculations over the coals. Although a 44 foot shot string is mathmatically feasible, in real life, 12 feet is a pretty long shot string.

+1 Good Comment? | | Report
from TommyNash wrote 5 years 2 weeks ago

I'll opt out of the physics calculations, tried that before with resounding failure. However I will take a few pops at the water for the real life application...hopefully I can piss off a few liberals to boot.

+3 Good Comment? | | Report
from WA Mtnhunter wrote 5 years 2 weeks ago

So, Phil

How much lead on a goose at 40 yards with 1450 fps steel shot BBB?

+1 Good Comment? | | Report
from duckcreekdick wrote 5 years 2 weeks ago

The math on this is way over the head of this country boy. I like Bob Brister's method of shooting duck silhouettes on a flat-bed trailer pulled by the family station wagon driven by his wife. There's trust for you!

+2 Good Comment? | | Report
from ken.mcloud wrote 5 years 2 weeks ago

Phil-

Agreed, though one interesting thing that simulation showed me is how the length of the shot string is HIGHLY dependent on how different the drag coefficients of the various BB's are from each other.

The length of your shot string could vary from a few inches to 44 feet (at 40yds) based on how tightly controlled the BB manufacturing process is.

I wonder if any of the ammo companies are looking into this?... I'll send them a resume if they are interested.

food for thought!!

+2 Good Comment? | | Report
from auburn_hunter wrote 5 years 2 weeks ago

ken.mcloud - From one enginerd to another, I appreciated your posts above. It really is amazing to think that the manufacturing process can effect the shotstring that dramatically. So it looks like it might actually be better to have a higher tolerance in place during the manufacturing process of the shot, thus leading to more birds being hit by the shooter!

+1 Good Comment? | | Report
from Amflyer wrote 5 years 2 weeks ago

All this nonsensical baloney can be easily calculated via the Solunar Tables.

+3 Good Comment? | | Report
from ken.mcloud wrote 5 years 2 weeks ago

Auburn_hunter-

It might actually be the other way around.

A low standard deviation in the shot pellet's drag coefficient would lead to short shot strings, thus allowing the bird/skeet to travel less distance during the time the shot is passing it. This makes the "window" where you have to aim to get a kill smaller.

If you ensure a large standard deviation in the shot pellet's drag coefficient you get a longer shot string. this allows the bird/skeet to travel a longer distance while the shot string is passing it thus, giving you a wider "window" to aim at in order to ensure a kill.

+1 Good Comment? | | Report
from idduckhntr wrote 5 years 2 weeks ago

Guncrazy said it best PRACTICE the guys on my trap team are engeniers and every time they miss they think they can calculate the shot and figure out why and I just tell them to throw that crap out the window and practice. Oddly enough I took some boys goose huntin once and mind you these are the guys that travel the US shootin in competion with there average is 100 straight every time but I'll be damn if the could'nt hit a goose at 15 yards go figure.

+3 Good Comment? | | Report
from WA Mtnhunter wrote 5 years 2 weeks ago

If the standard deviation applied to cx affects shot string length, what about the shot strings of mixed pellet loads like the Black Cloud, for instance?

+1 Good Comment? | | Report
from ken.mcloud wrote 5 years 2 weeks ago

idduckhntr-

You're right, There is no correlation between understanding the physics of a sport and being skilled at it.

I can write all the equations of motion for Tiger Woods' swing, yet for some reason I still shoot 20 over par.

On the other hand, I doubt Mr. Woods can write out those equations and he couldn't shoot a round as bad as mine if he was drunk and had an amputated arm!

The flip side of this coin is that if you want someone to design you a new golf club, the engineer can do a much better job than tiger can.

+1 Good Comment? | | Report
from ken.mcloud wrote 5 years 2 weeks ago

Wa mtnhunter-

The variation in the nonlinear damping coefficient is what cases the the shot string to elongate.

This coefficient is linearly dependent on the drag coefficient (the parameter I was varying), but it is dependent on the shot pellet's radius squared.

This means that doubling the variance in drag coefficient doubles the length of the shot string. However, doubling the variance in the shot pellet's radius quadruples the length of the shot string.

So, to answer your question, loads with multiple shot sizes will have EXTREMELY long shot strings. Much longer than those caused by variation in the drag coefficient.

+1 Good Comment? | | Report
from focusfront wrote 5 years 2 weeks ago

A little imprecision on the math aside, Phil's overall point, that you can't elongate or 'ovalize' a shot column by swinging the barrel of the shotgun as you fire, is still perfectly correct. And while it does seem unbelievable that an individual shot round could lose just about half its 1200 fps velocity in only forty yards, that too is correct. I've heard guys say that Hevi Shot cuts down on the amount of lead you need on a duck or pheasant, but haven't tested it myself. Anybody out there shoot that stuff at ducks and geese, or is it a turkey only proposition?

+2 Good Comment? | | Report
from WA Mtnhunter wrote 5 years 2 weeks ago

I have shot Hevi Shot, Bismuth, Hi Density, etc. on ducks and geese. Never on turkey. If 2 1/4 oz. of lead 4's won't get a gobbler, I need to quit.

As for waterfowl, I think the heavier non-toxic loads are a little more effective than steel, but as much as I shoot, it is cost prohibitive for me. Just let 'em get in a little closer and shoot bigger shot size.

+1 Good Comment? | | Report
from Mark-1 wrote 5 years 2 weeks ago

I don't believe steel shot is much good over 35-yards no matter what size shot used.

I have used plated shot....suppose to be better formed pellets....and chilled lead shot when it was legal, but I can't say there was a noticed difference...or I can't remember.

Physics: Spheres are lousy in retaining velocity. The only way to retain velocity in a sphere is via mass.

I don't believe birds are killed by shot velocity as they are killed by density of pattern IMHO.

+1 Good Comment? | | Report
from TommyNash wrote 5 years 2 weeks ago

Hey Auburn_hunter.....War Damn Eagle buddy!!

+2 Good Comment? | | Report
from auburn_hunter wrote 5 years 2 weeks ago

War Eagle, TommyNash!

Ken.mcloud - That's what I was trying to say - if you allow the tolerance to be higher (i.e. greater variation from given design specs), then the shooter would have a better chance of hitting the intended target. I may just not have conferred that properly.

+2 Good Comment? | | Report
from buck hunter 17 wrote 5 years 2 weeks ago

i always thought that it would. i shoult seend it in to MYTHBUSTERS because im to lazy to shoot my gun. JUst kiding i would rather do it my self so i can SEE that it is true and not false.

+2 Good Comment? | | Report
from shane wrote 5 years 2 weeks ago

People really thought they could do that?

+2 Good Comment? | | Report
from WA Mtnhunter wrote 5 years 2 weeks ago

ken.mccloud

Get those redneck War Damn Eagle engineers straightened out before the Tide comes in! LOL

+2 Good Comment? | | Report
from Del in KS wrote 5 years 2 weeks ago

Heavy shot is much better than any steel load on ducks and geese. Instant death is the norm where with steel every other bird is a cripple. For Turkey it adds about 15 yards of range to my SBE when using Remington #6 heavyshot. Most years I use 2 shots to tag out on Gobblers. The ammo is high but I don't use many.

+3 Good Comment? | | Report
from FloridaHunter1226 wrote 5 years 2 weeks ago

Its a myth that deffinantly gets people to follow through... if they say it will increase your odds at hitting the bird, people are going to fall into it and do it time after time.

+2 Good Comment? | | Report
from WA Mtnhunter wrote 5 years 2 weeks ago

Del in KS

I agree with your observation on Hevi-shot versus steel, particularly with geese. However, that crippled goose is no match for my Black Lab!

+2 Good Comment? | | Report
from nc30-06 wrote 5 years 2 weeks ago

I guess those who thinks this happens believe that if you swing a rifle barrel fast enough, you can generate an "out of the barrel" ricochet.

+3 Good Comment? | | Report

Post a Comment

from Mike Diehl wrote 5 years 2 weeks ago

How about we all trust the physics on this and NOT shoot at the "surface of the water."

+3 Good Comment? | | Report
from Quiet Loner wrote 5 years 2 weeks ago

I saw an article in American Rifleman several years ago on this. Someone constructed a big plywood wall mounted on a truck side. To give an idea of the age of the research, I believe it was a Ford Model A truck. They then drove the truck at various speeds past a stationary mounted shotgun as it was fired. Don't know how much they paid the driver. No matter how fast the truck went, patterns remained round.

+3 Good Comment? | | Report
from guncrazy74 wrote 5 years 2 weeks ago

I always flunked math but always get out and shoot as much as possible and I miss less. Good to know my priorities are straight.:)

+3 Good Comment? | | Report
from guncrazy74 wrote 5 years 2 weeks ago

Or as the old man says "Don't think, just shoot the damn thing!!"

+3 Good Comment? | | Report
from TommyNash wrote 5 years 2 weeks ago

I'll opt out of the physics calculations, tried that before with resounding failure. However I will take a few pops at the water for the real life application...hopefully I can piss off a few liberals to boot.

+3 Good Comment? | | Report
from Amflyer wrote 5 years 2 weeks ago

All this nonsensical baloney can be easily calculated via the Solunar Tables.

+3 Good Comment? | | Report
from idduckhntr wrote 5 years 2 weeks ago

Guncrazy said it best PRACTICE the guys on my trap team are engeniers and every time they miss they think they can calculate the shot and figure out why and I just tell them to throw that crap out the window and practice. Oddly enough I took some boys goose huntin once and mind you these are the guys that travel the US shootin in competion with there average is 100 straight every time but I'll be damn if the could'nt hit a goose at 15 yards go figure.

+3 Good Comment? | | Report
from Del in KS wrote 5 years 2 weeks ago

Heavy shot is much better than any steel load on ducks and geese. Instant death is the norm where with steel every other bird is a cripple. For Turkey it adds about 15 yards of range to my SBE when using Remington #6 heavyshot. Most years I use 2 shots to tag out on Gobblers. The ammo is high but I don't use many.

+3 Good Comment? | | Report
from nc30-06 wrote 5 years 2 weeks ago

I guess those who thinks this happens believe that if you swing a rifle barrel fast enough, you can generate an "out of the barrel" ricochet.

+3 Good Comment? | | Report
from NolanOsborne wrote 5 years 2 weeks ago

Good one Diehl!
while new to this.. i still admit that i beleived the shot pattern "slung abit"

+2 Good Comment? | | Report
from MLH wrote 5 years 2 weeks ago

I have seen high speed camera shots that show the shot string to be more 3D than I originally thought. But, with the velocities involved, I agree with you. We just can't move the barrel fast enough to string the pattern.

But I wonder if it helps some shooters to psych themselves into thinking that they are stringing the pattern along. Might be for the wrong reasons but it might help them keep the barrel moving.

+2 Good Comment? | | Report
from Jeff Bowers wrote 5 years 2 weeks ago

Thank you. I know someone who voiced this theory many years ago. I did not know enough to either agree or disagree with him. Sometimes you get to feel if somebody's done more of a thing than you (like shotgunning), they must know what they're talking about.

That is, until you get somewhere like here.

+2 Good Comment? | | Report
from focusfront wrote 5 years 2 weeks ago

The pattern will remain round no matter how fast you swing the barrel because the shot comes out of the barrel more or less as a unit. Only after leaving the barrel does it spread out.

That 'slinging shot' routine might be a good idea for the wrong reason, however. All us old rifle shooters want to aim the shotgun rather than point and swing it, and it goes against the grain for us to follow through with our swing after we pull the trigger. Slinging shot is a ballistic fallacy, but the idea that you are slinging shot might create a mindset that promotes swing and follow through. Which promotes hits. What do you think?

+2 Good Comment? | | Report
from buckhunter wrote 5 years 2 weeks ago

Thanks Phil. Maybe you can give some shooting advice to Michigan State. After lastnight it looks like they've been getting bad advice.

+2 Good Comment? | | Report
from Ralph the Rifleman wrote 5 years 2 weeks ago

This was target practice for WWII airplane machine gunners;man rode on a 1/2 rail car trailer while moving objects were tossed at them. Some of the "shotguns" looked like browning machine guns, too!

+2 Good Comment? | | Report
from WA Mtnhunter wrote 5 years 2 weeks ago

If an object moves at 40 mph, that is 5280 ft x 40 = 211,200 feet per hour. That is 3520 feet per minute and 58.66 feet (704 inches) per second or .05866 feet (.704 inch) in one one-thousandth of a second. So, in .016 seconds, a 40 mph duck moves 11.2 inches vice 4 inches.

Can you advise if my math is flawed?

+2 Good Comment? | | Report
from Mark-1 wrote 5 years 2 weeks ago

I can agree with the physics of the shotstring vs the old myths.

Upon shouldering and shooting some of those very old shotguns I don’t know how people hit with them. The idea of keeping the swing going and “get way out front” makes sense when I consider the relatively slow lock and ignition times with these old guns.

I thought the old muzzleloading cap shotguns bad. Then I tried shooting clays with a flintlock shotgun. What a trip.

Those old shooters must have shot with their heads high. Stocks on those old doubles have too much drop for me. I’m always looking below the receiver into the tang when I shoulder them.

+2 Good Comment? | | Report
from Mark-1 wrote 5 years 2 weeks ago

WA,

Think you have the duck going the speed of the shot string in your calc's, not at 40 mph.

+2 Good Comment? | | Report
from Beekeeper wrote 5 years 2 weeks ago

Old ideas die a long and miserable death... We will forgive the physics lesson, just keep those barrels moving guys and gals!

+2 Good Comment? | | Report
from ishawooa wrote 5 years 2 weeks ago

It has always been my observation that my best shotgunning was performed using IC choke with the game within a reasonable distance due to the quicker and wider spread of the pattern.
This brings to mind another shotgun story. Once at a deep camp down south where shotguns only were allowed I overheard a younger hunter ask an older guy why it was not a good choice to use a full choke to shoot buckshot. The wily old fellow squinted his eyes and replied "If you use the tight choke the buckshot have to wait their turn to get out of the end of the barrel".

+2 Good Comment? | | Report
from HogBlog wrote 5 years 2 weeks ago

Can't say I've ever heard the shot stringing myth, but from some of the other shooting mythology, I can see how people would come up with it.

+2 Good Comment? | | Report
from ken.mcloud wrote 5 years 2 weeks ago

Wa mtnhunter is right.

a object moving at 40 mph travels 11.264 inches in .016 seconds.

No offense phil, but given this error I ran over the rest of your math, just to be sure.

It looks like you assumed the shot was moving at 625 ft/sec when 40 yds from the muzzle. When you assume a muzzle velocity of 1200 ft/sec that leads to an average deceleration of 135.89 G's.

That rate of deceleration seems way out of whack for anything but an impact shocks.

So, I whipped out Matlab and did a little non-linear dynamic simulation. I assumed you shot #8 lead shot at sea level with a muzzle velocity of 1200 ft/sec and a drag coefficient of .1 on each pellet. This ignores interactions between shot pellets but should get us in the ballpark.

This produced a shot velocity of 712.5 ft/sec at 40 yds downrange. So, I guess your estimate of 625 ft/sec was pretty reasonable.

(for those keeping score, Phil now is 1 for 2)

I then varied the drag coefficient from .1 to .4 (an acceptable range for a sphere). I got that at 40 yds the shot-string could be as spread out as 44 ft in the direction of the shot. I found this VERY surprising. I expected it to be much shorter.

So, again your estimate of 10 ft was at least in the right ballpark (or as us engineers say, on the right order of magnitude)

(Phil is now 2 for 3)

to wrap things up, I assumed a worst case shot-string length of 44 feet, and a shot velocity of 625 ft/sec. This would pass the duck in .0704 seconds. The 40 mph duck moves 4.13 feet during the time the shot is passing him.

(And the final score is 2 for 4!, about the same ratio as my NCAA bracket!)

So, after all that math we see that a large variation in the drag coefficient leads to a long shot-string which makes the duck easier to hit. (unfortunately this variation is essentially impossible to control and could be much smaller)

Since the length of the string at the muzzle is essentially zero, your swing will really not effect this length at all.

Conclusion: Phil is right, even if his math is a little off.

+2 Good Comment? | | Report
from Clay Cooper wrote 5 years 2 weeks ago

Reminds of the myth of the old Vietnam story about M16 bullets are designed to tumble instantly breaking the muzzle. First of all, if this was true then why does the M16 have rifling to begin with and if it did tumble the barrel is washed out requiring replacement.

The truth about this is, the M16A1 has a 1-14 twist for a 55 grain FMJ that is barely stabilized. Because the bullet is barely stabilized, the bullet instantly tumbles upon impact with devastating results!

+2 Good Comment? | | Report
from duckcreekdick wrote 5 years 2 weeks ago

The math on this is way over the head of this country boy. I like Bob Brister's method of shooting duck silhouettes on a flat-bed trailer pulled by the family station wagon driven by his wife. There's trust for you!

+2 Good Comment? | | Report
from ken.mcloud wrote 5 years 2 weeks ago

Phil-

Agreed, though one interesting thing that simulation showed me is how the length of the shot string is HIGHLY dependent on how different the drag coefficients of the various BB's are from each other.

The length of your shot string could vary from a few inches to 44 feet (at 40yds) based on how tightly controlled the BB manufacturing process is.

I wonder if any of the ammo companies are looking into this?... I'll send them a resume if they are interested.

food for thought!!

+2 Good Comment? | | Report
from focusfront wrote 5 years 2 weeks ago

A little imprecision on the math aside, Phil's overall point, that you can't elongate or 'ovalize' a shot column by swinging the barrel of the shotgun as you fire, is still perfectly correct. And while it does seem unbelievable that an individual shot round could lose just about half its 1200 fps velocity in only forty yards, that too is correct. I've heard guys say that Hevi Shot cuts down on the amount of lead you need on a duck or pheasant, but haven't tested it myself. Anybody out there shoot that stuff at ducks and geese, or is it a turkey only proposition?

+2 Good Comment? | | Report
from TommyNash wrote 5 years 2 weeks ago

Hey Auburn_hunter.....War Damn Eagle buddy!!

+2 Good Comment? | | Report
from auburn_hunter wrote 5 years 2 weeks ago

War Eagle, TommyNash!

Ken.mcloud - That's what I was trying to say - if you allow the tolerance to be higher (i.e. greater variation from given design specs), then the shooter would have a better chance of hitting the intended target. I may just not have conferred that properly.

+2 Good Comment? | | Report
from buck hunter 17 wrote 5 years 2 weeks ago

i always thought that it would. i shoult seend it in to MYTHBUSTERS because im to lazy to shoot my gun. JUst kiding i would rather do it my self so i can SEE that it is true and not false.

+2 Good Comment? | | Report
from shane wrote 5 years 2 weeks ago

People really thought they could do that?

+2 Good Comment? | | Report
from WA Mtnhunter wrote 5 years 2 weeks ago

ken.mccloud

Get those redneck War Damn Eagle engineers straightened out before the Tide comes in! LOL

+2 Good Comment? | | Report
from FloridaHunter1226 wrote 5 years 2 weeks ago

Its a myth that deffinantly gets people to follow through... if they say it will increase your odds at hitting the bird, people are going to fall into it and do it time after time.

+2 Good Comment? | | Report
from WA Mtnhunter wrote 5 years 2 weeks ago

Del in KS

I agree with your observation on Hevi-shot versus steel, particularly with geese. However, that crippled goose is no match for my Black Lab!

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from Mark-1 wrote 5 years 2 weeks ago

Ooops. WA,

Your cacl's are within .66 ft of mine @ 40 mph. Not enough to make a squat of difference of what you figured that duck would move.

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from philbourjaily wrote 5 years 2 weeks ago

WAMtnhunter -- My math is backward. You convert MPH to FPS by multiplying by 88/60, except I always do 60/88 by mistake.
Ken McCloud -- Thanks for taking the time to rake my calculations over the coals. Although a 44 foot shot string is mathmatically feasible, in real life, 12 feet is a pretty long shot string.

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from WA Mtnhunter wrote 5 years 2 weeks ago

So, Phil

How much lead on a goose at 40 yards with 1450 fps steel shot BBB?

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from auburn_hunter wrote 5 years 2 weeks ago

ken.mcloud - From one enginerd to another, I appreciated your posts above. It really is amazing to think that the manufacturing process can effect the shotstring that dramatically. So it looks like it might actually be better to have a higher tolerance in place during the manufacturing process of the shot, thus leading to more birds being hit by the shooter!

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from ken.mcloud wrote 5 years 2 weeks ago

Auburn_hunter-

It might actually be the other way around.

A low standard deviation in the shot pellet's drag coefficient would lead to short shot strings, thus allowing the bird/skeet to travel less distance during the time the shot is passing it. This makes the "window" where you have to aim to get a kill smaller.

If you ensure a large standard deviation in the shot pellet's drag coefficient you get a longer shot string. this allows the bird/skeet to travel a longer distance while the shot string is passing it thus, giving you a wider "window" to aim at in order to ensure a kill.

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from WA Mtnhunter wrote 5 years 2 weeks ago

If the standard deviation applied to cx affects shot string length, what about the shot strings of mixed pellet loads like the Black Cloud, for instance?

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from ken.mcloud wrote 5 years 2 weeks ago

idduckhntr-

You're right, There is no correlation between understanding the physics of a sport and being skilled at it.

I can write all the equations of motion for Tiger Woods' swing, yet for some reason I still shoot 20 over par.

On the other hand, I doubt Mr. Woods can write out those equations and he couldn't shoot a round as bad as mine if he was drunk and had an amputated arm!

The flip side of this coin is that if you want someone to design you a new golf club, the engineer can do a much better job than tiger can.

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from ken.mcloud wrote 5 years 2 weeks ago

Wa mtnhunter-

The variation in the nonlinear damping coefficient is what cases the the shot string to elongate.

This coefficient is linearly dependent on the drag coefficient (the parameter I was varying), but it is dependent on the shot pellet's radius squared.

This means that doubling the variance in drag coefficient doubles the length of the shot string. However, doubling the variance in the shot pellet's radius quadruples the length of the shot string.

So, to answer your question, loads with multiple shot sizes will have EXTREMELY long shot strings. Much longer than those caused by variation in the drag coefficient.

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from WA Mtnhunter wrote 5 years 2 weeks ago

I have shot Hevi Shot, Bismuth, Hi Density, etc. on ducks and geese. Never on turkey. If 2 1/4 oz. of lead 4's won't get a gobbler, I need to quit.

As for waterfowl, I think the heavier non-toxic loads are a little more effective than steel, but as much as I shoot, it is cost prohibitive for me. Just let 'em get in a little closer and shoot bigger shot size.

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from Mark-1 wrote 5 years 2 weeks ago

I don't believe steel shot is much good over 35-yards no matter what size shot used.

I have used plated shot....suppose to be better formed pellets....and chilled lead shot when it was legal, but I can't say there was a noticed difference...or I can't remember.

Physics: Spheres are lousy in retaining velocity. The only way to retain velocity in a sphere is via mass.

I don't believe birds are killed by shot velocity as they are killed by density of pattern IMHO.

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