Fast cartridge vs slower cartridge

[TIGHTCHOKE]

Just another pace!

[Guest cookoff013]

just prefer big heavy large shot loads. 

but for small light informal, 28g loads are not that bad.

 

[figgy]

So does a 1200fps 7.5 reach the target at say 50 yards at the same time as a 1200fps 3 at the same time? 

Retained velocity of the larger shot must play a part in keeping it going faster for longer. 

I agree that picking a cart for its pattern and shooting characteristics is more important that speed for clays and game with lead or heavy non tox. 

[wymberley]

12 hours ago, figgy said:

So does a 1200fps 7.5 reach the target at say 50 yards at the same time as a 1200fps 3 at the same time? 

No, about 26 millisecs later

Retained velocity of the larger shot must play a part in keeping it going faster for longer. 

As above

I agree that picking a cart for its pattern and shooting characteristics is more important that speed for clays and game with lead or heavy non tox.

Yep, provided you don't blow the pattern with too high a speed of the latter, in most cases it doesn't really matter whether you use a thunderball or a streak of lightening. The only time the smaller pellet has the advantage is when both (having the same energy) are getting towards the lower (but sufficient) end of their effective energy level. At this point the smaller is the more lethally efficient. Energy density again.

 

[Guest cookoff013]

the one bug i have is the concepts that something shot slower is always going to arrive at the target faster than a faster shot.

its just nonsense how can something with more energy and the same energy retention over distance outperform a lesser energy shot.

what external ballistics are is the relationships between starting speed or energy and retained or lost energy and of course the final reading of energy / speed at x distance.

going up shot size will always outperform something of smaller size, shotguns are really simple. lots of shot, big enough usually does the trick on anything. 

now external ballistics are not my forte as it were, but i have understanding of energy, energy retention, energy loss, speed loss (same thing really) and energy at x. while these are very useful in determining how powerful a cartridge is, things arnt always as it seems, take the american turkey loads 1300fps or so 2oz of #9. it has a silly amount of energy involved, at the begining something like 2500ftlbs of energy, at 30yards, if at all 50% (1oz shot) makes it on target with 400odd fps. is not alot of energy really. 

taking the opposite, 1oz slug 1200fps delivers a heck of alot of energy on target (relative). i know one is shot and one is slugs.

the #6 is quite a shotsize as it is more acceptable for game shooting, (steady on) but the argument that #7 fills more gaps is a half argument. 28g #6 vs 32g#6 (the 32g fills more gaps)

but then 36g #4 puts alot on target. (or can )

[wymberley]

"Things arnt always as it seems"

True enough.

[Fen tiger]

The Essential Ed Lowry on Shotshell Velocity and Patterns (from Shotshell Ballistics for Windows 3.1

 

 

ACTUAL MUZZLE VELOCITY

 

It has been the industry practice to give the initial velocity of a shotshell load as its velocity at three feet from the muzzle, as measured with a coil disjunctor. This situation is further complicated by the fact that the physical configuration of the shot column at three feet causes the coil disjuntor to produce a somewhat misleading measurement.

 

For example, when a moving shot column passes through a full choke constriction, the column strings out to several times its original in-bore length. The front pellets quickly separate and are immediately in free flight. Moreover, at three feet from the muzzle, these front pellets are the only ones in free flight since the remaining pellets in the column, although no longer in contiguous contact, have not yet begun to disperse and are still traveling in the turbulent wakes of others. The coil disjuncter actually produces the average velocity of the entire shot column. But it is the velocity of the forward pellets that determines the average downrange performance of the whole shot charge.

 

Hence, in order to ascertain the actual velocity at the muzzle, two corrections to the three foot measurement must be made. The first one increases the three-foot value by an amount that depends on pellet type and pellet size and by the amount of choke constriction.* The second correction then simply produces the muzzle velocity necessary to give the (corrected) resulting three-foot velocity.

 

• The basis for this was established in an extensive experimental program by the Winchester Research Department in 1969.

 

MEASURING THE PATTERN

 

A shotshell pattern is a large signature sheet on which is recorded the impact locations of pellets from a moving shot cloud. Its purpose is to provide a measure of lateral pellet dispersion at some predetermined downrange point. In current practice the standard measure of this dispersion is the pattern percentage. To obtain its value, the user places the signature sheet on a flat surface and then determines the largest number of pellet holes that can be covered by a 30 circle. The pattern percentage is this number, divided by the total number of pellets in the load, times 100.

 

The customary downrange location of a signature sheet is at 40 yards. Hence when a gun-ammunition combination is said to give a certain pattern percentage, it is generally understood (unless otherwise specified) that the percentage number refers to its average value at 40 yards.

 

 

THE BELL-SHAPED CURVE

 

After the pellets in a shot charge clear the muzzle, and are in free flight, each of their individual flight paths experiences a number of deflections which vary randomly in both direction and magnitude. The deflections of any one pellet, moreover, are unaffected by those of any so that the pellets all move independently. Yet, collectively, their points of impact produce a definable frequency distribution on the signature sheet.

 

The dispersion of pellet holes on a signature sheet conforms to the so-called "normal" or "Gaussian distribution", more familiarly known as the "bell shaped curve". This was reported by Journee in his 1902 "Tir de Fusils de Chasse", subsequently corroborated with hundreds of patterns at the Western Cartridge Co. (now the Winchester Division of Olin Corp.) in 1946 and also publicly reported by Oberfell and Thompson in 1957. A further number of extensive experimental programs at the Winchester research range established the effects of range, choke constriction, shot size and atmospheric conditions on pattern values.

 

EFFECT OF ATMOSPHERE ON PATTERNS

 

For ballistic purposes of reference, "Standard Atmospheric Conditions" are: a temperature of 59 degrees F (15 degrees C); a barometric pressure of 29,54 " (75 cm) mercury, at sea-level; an absence of wind ; and a relative humidity of 50%. Deviations from these reference conditions will have the following effects on ballistic performance.

 

1. Temperature A rise in temperature causes a drop in air density and, thereby, a drop in the drag forces that decelerate a moving pellet and that induce its dispersive (i.e. patterning) behavior.

2. Barometric Pressure A rise in barometric pressure causes a rise in air density, and thus an increase in the aerodynamic drag force. At near sea-level (1000 foot altitude or less) conditions, which characterize the overwhelming amount of populated land in the U.S., the normal changes in barometric pressure cause such a small change in air density that the ballistic effects are negligible. However, the effect of altitude on the average barometric pressure can be considerable.

3. Wind Head and tail winds (i.e. those moving toward or away from the shooter) have a small effect on downrange velocities and an almost negligible effect on patterning. A cross wind has essentially no effect on effect on velocity or dispersion. However, a cross wind can cause sensible lateral movement of the shot cloud.

4. Humidity Humidity, even rain, has a negligible effect on downrange ballistic performance and is therefore not considered.

 

SHOTSTRING EFFECTS

 

As a cloud of pellets flies toward a target its individual pellets disperse, both laterally (patterning) and longitudinally.(shotstring). The way that a shot cloud disperses laterally is covered by the "Shotshell Patterning" and by the "Target Hits" sections of this Shotshell Ballistics program. This lateral dispersion is further covered under "Miscellaneous Topics". While pattern measurements are readily obtainable, as is done with downrange signature sheets, the measurement of a shotstring is not so easily managed. Methods for shotstring measurements are covered in the three references listed below.

 

The pertinent property of a shotstring is its length. This is usually specified (in the US) as the shortest length that includes 90% of the load's pellets at 40 yards from the muzzle. The key question about a load's shotstring centers on the relative effect of its length on the load's lethal effectiveness this question breaks down into two parts: the effect on pellet energy delivery and the effect on the total number of hits delivered against the target.

 

The effect of shotstring length on energy delivery is difficult to ascertain. A long shotstring, which represents a large spread in pellet travel-times, suggests that the trailing pellets in the shot cloud are meaningfully smaller and/or more distorted than the leading pellets. But the actual degrees of pellet size variation and of pellet deformation are not easily predictable. Moreover, since the actual value of the shotstring length for any given shotshell load can only be roughly conjectured, a procedure with poorly known input values is only marginally useful. For this reason the "Shotstring Ballistics" routine does not predict downrange ballistic behavior. Instead it aims simply to illustrate the nature of the shotstring problem and chooses to do this with at the one range, namely at 40 yards.

 

However, the way that shotstring length affects the average number of target hits, (without reference to delivered pellet energy) is more readily ascertainable. This is demonstrated here with the help of the following arbitrarily chosen example:

 

 

Ammunition 12 gauge, 1-1/4 oz of #2 steel shot, 3-foot velocity is 1365 ft/sec; 80% of pellets hit within 30" circle at 40 yards (assumed);

Target Size 20 square inches (e,g, the vulnerable area of a mallard);

Target Range 40 yards;

Target Speed 70 ft/sec, traveling at right angle to the line of fire;

Flight Time 0.126 seconds, for shot to travel 40 yards;

Lead Distance 8.82 feet (106"), traveled by target while shot travels 40 yards

Shotstring Ratio of Average Number of Hits if Shooter's Lead

Length in Shot Velocity to Is Dead Is Off by

Feet Target Velocity On 10 Inches

0 9.94 6.90 3.43

5 9.94 6.60 3.38

10 9.94 5.96 3.26

15 9.94 4.86 2.97

20 9.94 3.97 2.65

 

References:

1 - Bob Brister - Shotgunning, The Art and The Science, (Chapter on The Shot String Story) Winchester Press, 1976

2 - Gerald Burrard - The Modern Shotgun, (Chapters V and VI) A.S. Barnes and Co., Inc. New York, 1961

3 - E.D. Lowry - The Effect of a Shotstring, The American Rifleman, November 1979

 

FELT RECOIL

 

Various experiments have shown that the disagreeable "kick" sensation experienced by the shooter correlates primarily with the kinetic energy that has been imparted to his recoiling gun. The total sensation is probably influenced by other factors that are difficult to measure, such as the method of holding, the resulting noise, etc. But a gun's recoil energy can be established from the known properties of the gun and of the ammunition.

 

Determination of a shotgun's recoil energy follows directly from the laws of motion established by Isaac Newton. One direct consequence of these laws is the principle of the conservation of momentum. It tell us that if we let

 

 

W be the gun's weight.

V be the gun's recoil velocity.

ws be the shot charge weight.

ww be the weight of the wad.

v be the muzzle velocity.

pw be the propellant weight.

pv be the average velocity (at the muzzle) of the propellant gases.

Then

[W times V] is equal to: [(ws + wv) times v] plus [pw times pv].

 

For a given gun and shotshell load, six of the above quantities are assumed to be either measurable or known. The seventh, the gas velocity (actually the velocity of sound in the propellant gases), is approximately 4,000 feet per second for shotshell propellants. Hence, if all quantities are given in pounds or feet per second, then it follows from algebraic manipulation and from the definition of kinetic energy that the gun' s recoil energy is given as

 

[M times V squared] divided by [2 times g], where

g is the gravitational constant and assumed as 32.16 ft/dec/sec.

 

LAG TIME

 

An example can demonstrate the meaning of lag time. Suppose that a projectile, aimed at a target 40 yards downrange, leaves a gun muzzle at a velocity of 1,200 feet per second. If there were no air resistance the projectile would travel the 120 foot distance in one tenth of a second.

 

But, there is air resistance in our atmosphere. Suppose also, for our example, that the projectile is a #2 steel shotshell pellet and the atmosphere is at standard conditions (59 degrees F and 29.54" barometric pressure). In this case the pellet would require .1457 instead of .1000 seconds to travel the120 feet. Thus air resistance slows the pellet and causes it to arrive .0457 seconds late. The .0457 second delay is the "lag time".

 

The meaning of lag distance is definable in a similar manner. If there were no air resistance during the .1457 second travel time it takes the #2 steel pellet to travel the 120 feet, then it would travel at 1200 ft/sec for .1457 seconds. In such a case the pellet would travel a total distance of

 

(1,200) times (.1457) = 174.84 feet.

 

The extra distance, 174.84 - 120 = 54.84 feet (call it 55), is the extra distance that did not get traveled because of the rearward push of air resistance. This 55 foot distance is the "lag distance".

 

FLYING SPEED OF GAME

 

Approximate Flying Speeds of some Gamebirds

(in feet per second)

 

 

GAMEBIRD MINIMUMSPEED MAXIMUMSPEED MEDIANSPEED

black duck 50 90 70

blue-wing teal 70 90 80

bob-white 60 80 70

brant 70 90 80

cackling goose 80 100 90

california quail 60 80 70

canada goose 70 90 80

canvasback 90 100 95

cinnamon teal 70 90 80

gadwall 65 85 75

golden eye 60 90 75

green-wing teal 70 90 80

mallard 50 90 70

mourning dove 50 80 65

pheasant 60 90 75

pintail 60 80 70

redhead 75 95 85

ruffed grouse 40 60 50

sharptail grouse 50 70 60

snow goose 60 90 75

spoonbill 50 90 70

turkey 60 90 75

widgeon 65 85 75

 

BALLISTIC COEFFICIENTS

 

A shotshell pellet's ballistic coefficient is a comparative measure of its ability to overcome the force of air resistance. It is numerically equal to the pellet's sectional density divided by a so called form factor, which is an index of pellet shape. The pellet's sectional density is equal to its weight (in lb) divided by the the square of its diameter (in inches). The form factor for a truly spherical pellet is equal to one (1.0). Hence, for an undeformed, spherical pellet, the ballistic coefficient is simply equal to its sectional density.

 

If two dissimilar pellets have the same ballistic coefficient and are launched with the same muzzle velocity, their velocitites (and flight times) at any downrange point will be the same. Thus, as seen in the table below, a #5 steel pellet and a Buffered Lead #8-1/2 pellet will have identical downrange velocities (and flight times) if they are each of equal roundness in flight and if each is launched with the same muzzle velocity.

 

SECTIONAL DENSITY OF SOME EXAMPLE SHOTSHELL PELLET TYPES

 

SHOTSIZE STEEL BISMUTH IRON-TUNGSTEN BUFFEREDLEAD

#9 0.080" 0.0119 0.0147 0.0157 0.0168

#8½ 0.085" 0.0126 0.0156 0.0167 0.0178

#8 0.090" 0.0134 0.0165 0.0177 0.0189

#7½ 0.095" 0.0141 0.0174 0.0187 0.0199

#7 0.100" 0.0149 0.0183 0.0196 0.0210

#6½ 0.105" 0.0156 0.0192 0.0206 0.0220

#6 0.110" 0.0164 0.0202 0.0216 0.0231

#5 0.120" 0.0178 0.0220 0.0236 0.0252

#4 0.130" 0.0193 0.0238 0.0255 0.0273

#3 0.140" 0.0208 0.0257 0.0275 0.0294

#2 0.150" 0.0223 0.0275 0.0295 0.0315

#1 0.160" 0.0238 0.0293 0.0314 0.0336

B 0.170" 0.0253 0.0312 0.0334 0.0357

BB 0.180" 0.0268 0.0330 0.0353 0.0378

BBB 0.190" 0.0283 0.0348 0.0373 0.0399

T 0.200" 0.0297 0.0367 0.0393 0.0420

TT 0.210" 0.0312 0.0385 0.0412 0.0441

F 0.220" 0.0327 0.0403 0.0432 0.0462

FF 0.230" 0.0342 0.0421 0.0452 0.0483

 

 

 

[wymberley]

A thoroughly comprehensive post.

Since it was written, our BRL in its 1996 report to Defra has detailed vast improvements in our understanding of the behaviour of shot string.

With regard to the final piece on BCs, if you run our traditionally held figures through a ballistic calculator - lets say our No 7 it'll give c549 ft/sec and c0.9 ft lbs for 50 yards. c50 yard pigeon with No 7 sounds about right as a maximum perhaps. If you take the American equivalent #71/2 and use the sectional density which it states equates to the BC, then the figures will be c842 ft/sec and c2 ft lbs and the 0.9 ft lbs comes up a bit further on at c109 yards. Muzzle velocity used in both cases was was 1500 ft/sec. A 109 yard range for pigeon with our No 7? Nah, think i'll stick with our version of things.

[Fen tiger]

1 hour ago, wymberley said:

A thoroughly comprehensive post.

Since it was written, our BRL in its 1996 report to Defra has detailed vast improvements in our understanding of the behaviour of shot string.

With regard to the final piece on BCs, if you run our traditionally held figures through a ballistic calculator - lets say our No 7 it'll give c549 ft/sec and c0.9 ft lbs for 50 yards. c50 yard pigeon with No 7 sounds about right as a maximum perhaps. If you take the American equivalent #71/2 and use the sectional density which it states equates to the BC, then the figures will be c842 ft/sec and c2 ft lbs and the 0.9 ft lbs comes up a bit further on at c109 yards. Muzzle velocity used in both cases was was 1500 ft/sec. A 109 yard range for pigeon with our No 7? Nah, think i'll stick with our version of things.

Another less relative to this post but  still interesting piece by the late  Ed Lowry

http://discovery.ucl.ac.uk/1382490/1/396689.pdf

Some old debate on DHC on Gaussian distribution

http://www.duckhuntingchat.com/forum/viewtopic.php?f=14&t=150934&mobile=desktop

Edited December 14, 2017 by Fen tiger

[wymberley]

Re the first link above, David, while studying for his Phd, worked with  Dr Roger Giblin at the BRL and is a co-author of the final report.

[neutron619]

23 hours ago, wymberley said:

With regard to the final piece on BCs, if you run our traditionally held figures through a ballistic calculator - lets say our No 7 it'll give c549 ft/sec and c0.9 ft lbs for 50 yards. c50 yard pigeon with No 7 sounds about right as a maximum perhaps.

GS (and other) ballistic coefficients for various shot sizes at various velocities for various substances can be found here:

https://www.cfsa.co.uk/pages/public/shotgunPellet.aspx

Use the selectors to choose the combination you're after.

Observe the significant increase in the rate of efficiency as velocity drops.

Edited December 15, 2017 by neutron619

[wymberley]

1 hour ago, neutron619 said:

GS (and other) ballistic coefficients for various shot sizes at various velocities for various substances can be found here:

https://www.cfsa.co.uk/pages/public/shotgunPellet.aspx

Use the selectors to choose the combination you're after.

Observe the significant increase in the rate of efficiency as velocity drops.

Not too sure what to make of the above link, but as said before, I'm not the brightest cherry. Staying with the UK7 and running the 2% antimony GS at the worst possible level throughout - the 1500 ft/sec -  this still gives a 0.9 ft/lb figure in excess of 100 yards on my Ballistic programme (I'm not saying I use the 0.9 level, simply that that is about the oft quoted requirement for killing various.

Could you help me out here and run 0.00886. Cheers

EDIT: On reflection, all I can come up with is if the figures in the above link and those in FT's post are correct then they could possibly relate to an alternative base formula to that which we - not to mention Sierra in their Infinity Suite -  have historically used and one which i'm not aware of.

Edited December 15, 2017 by wymberley

[Ultrastu]

Looking at those bc figures for lead shot sizes .I think they are way way off .

It says a no6 shot has a bc of 0.0231 No way .that would be the similar to a 10 grn round head .177 pellet fired around 800 fps. .

Also we must remember bc values  change with muzzle velocity. And also over the range they are measured .So of you calculate a bc .Over say 20 yds .

The exact same value would be different if you calculated it over 40 yds .

Bc is a guide to energy retention at best. And is generally  accepted as being far from a precise means of working out the retained energy or velocity of a projectile. 

 

[Alycidon]

Buy a cartridge and STICK TO IT.    You will have good days and bad but you will know its not the cartridge that is at fault.

I had a clearout of my odds and **** the other day,  everything from 15 year old 32 gr VIP7s  ( 1475 fps ?) through to 28gr Impax of a similar age (1350 fps) and sundry other odds and ends from Gamebore and Hull.  I did select the first two yes but from then on stuffed them in as they came to hand.  My kills to cartridge rate was actually slighter better than normal.

Talking of patterning that old boy from Yorkshire way has lots of vids killing very high birds with a pair of Miroku's,  he patterns all his loads at his usual working range ( 55 yards).   To me his patterns looks awfull,  but he likes them and they work.       Personally I am not a good enough shot to worry to much about that,  30gr of 5s ( VIP Game felt wad as you ask !!) through 1/2 + 3/4 or 1/4 + 1/2 will kill anything flying I wish to kill if I can place the pattern on it.  But I dont push the range envelope that often.

 

A

[neutron619]

14 hours ago, wymberley said:

Not too sure what to make of the above link, but as said before, I'm not the brightest cherry. Staying with the UK7 and running the 2% antimony GS at the worst possible level throughout - the 1500 ft/sec -  this still gives a 0.9 ft/lb figure in excess of 100 yards on my Ballistic programme (I'm not saying I use the 0.9 level, simply that that is about the oft quoted requirement for killing various.

Could you help me out here and run 0.00886. Cheers

EDIT: On reflection, all I can come up with is if the figures in the above link and those in FT's post are correct then they could possibly relate to an alternative base formula to that which we - not to mention Sierra in their Infinity Suite -  have historically used and one which i'm not aware of.

 

12 hours ago, Ultrastu said:

Looking at those bc figures for lead shot sizes .I think they are way way off .

It says a no6 shot has a bc of 0.0231 No way .that would be the similar to a 10 grn round head .177 pellet fired around 800 fps. .

Also we must remember bc values  change with muzzle velocity. And also over the range they are measured .So of you calculate a bc .Over say 20 yds .

The exact same value would be different if you calculated it over 40 yds .

Bc is a guide to energy retention at best. And is generally  accepted as being far from a precise means of working out the retained energy or velocity of a projectile. 

 

I am assuming that you both understand that a BC of 0.028 for the GS drag function means something very different to a BC of 0.028 for the G1 drag function (which you'd use for air rifle pellets)?

Put another way, if you stuck the GS number into the G7 function, your #7 pellet would probably have 0.9ftlbs at 200 yards, not 100 (Edit: I haven't worked this out, but the range would be greater).

Your air rifle pellet BC's are almost certainly G1 numbers. As for what wymberley is calculating, hard to predict, but I'd suggest it's a drag function which doesn't represent a spherical form factor, on the basis that his provided BC is lower and therefore probably appropriate to a more ballistically-efficient form factor (e.g. the G1 "artillery" form) which would mean that the lower ballistic efficiency of a spherical projectile analyzed with the G1 function would result in a lower BC.

I hasten to add that if you go the other way and calculate G1 coefficients for spherical projectiles, they will probably be way out, particularly at low velocities, because - as above - the form factor associated with the drag function will be completely wrong for the projectile in question.

In fact, analagous to the above, in the GS-to-G1 case they'll vastly over-estimate the BC's at lower velocity because you're not dealing with a tubular projectile of given mass and sectional density, but a sphere. The effect is, essentially, and in terms of the calculations only, that the mass is treated as being much more efficiently packed into the space, giving the impression that the projectile is much more efficient than it actually is. One way to think about it would be to say that the contradiction between sectional density and mass values implied by the change in drag function, gives an increase in apparent projectile density. This is wrong in so many ways, but it's why the G1 function will often over-estimate efficiency for spherical projectiles (Edit: if you feed it GS / GS1929 BC's).

As for the numbers, there's nothing wrong with them in a strict sense as far as I'm aware. They've been checked, re-checked and independently checked by people much cleverer than me, and found to be valid. I think it's just a question of whether they're used correctly.

The same software / calculations that create those BC's - and they aren't a lot of practical use, I'll agree with you there - come with a whole load of tests to "sanity check" them, one of which is that the maximum range of a #5 pellet fired at 1450fps at a 33° angle of elevation in still, standard atmospheric conditions is about 299 metres. Nothing to argue with there, I think. There are some tests modelling .308 trajectories which are also perfectly sensible too, so it's a broad range of testing they do.

Most importantly for this case, in the #5 pellet test, the BC of the pellet is not used to calculate the trajectory (but may be calculated for any given point along it) which avoids a circular reliance on an incorrect value (avoiding the possibility that an initial error proves itself to be "correct" by creating a whole series of apparently reasonable numbers based upon itself). There's also that and the fact that if you do around 10,000,000 calculations in an iterative fashion, then anything non-sensical tends to show up pretty quickly, as every iteration will tend to magnify any previous errors... It seems clear that this isn't happening from my analysis of the data.

PM me if you want to know more about the software in question.

Edited December 16, 2017 by neutron619
Clarity.

[TIGHTCHOKE]

Thank you Professor, keep up the good work.

[Guest stevo]

What ever happened to just enjoying them , you know just getting out and shooting the things , 

 

i think the the biggest problem nowadays that most seem to have is trying to replace instinct with science. 

 

Shame ?

[Ultrastu]

There is no harm in understanding the science behind shooting it only adds to the enjoyment in my book .

The trigger pulling bit can still be simple and instinctive. 

But the internal / external / terminal ballistics is fascinating 

[Guest stevo]

29 minutes ago, Ultrastu said:

There is no harm in understanding the science behind shooting it only adds to the enjoyment in my book .

The trigger pulling bit can still be simple and instinctive. 

But the internal / external / terminal ballistics is fascinating 

Hey stu , I’m all for learning but int/ext ballistics with shotshells is nothing more than best guessing .  No two shellsl can be replicated , 

i pattern all my guns for gun fit ( note I said guns NOT shells)  the above rules apply , no two patterns will ever be the same , and to really throw a spanner in the works try shooting though five pattern plates at 5m intervals starting at 20 ,30 , 35 , 40 , 45 yards. The pattern does not just get bigger at constantly changing shape to . So a waste of time .

if you want to talk basic rules of thumb , here’s mine and most of the old farts I have shot with over the past 40 yrs .

a slow cartridge patterns tighter than a fast cartridge , therefore a slower shell tends to hit harder as it’s a denser pattern ( pattern kills )

I packed up shooting live game 18 months ago , after 30 odd yrs of pigeon shooting . I  now shoot fast trap competitively   (ABT , OT, UT )

my comp shells are 28 gram of English 7 , manufacturers say there 1400 FPS  . These pattern tight as there not fast , which when shooting an edge on target at 75-80 mph is a must . I have always felt there is way too much of a trade off when it comes to speed . 

 

One or the other gentlemen .......  you can’t have both . 

Edited December 17, 2017 by stevo

[Ultrastu]

I agree with you very much .

And clearly you Also think about your guns and how it works and what it does .

Can i ask why you gave up the live stuff ? 

Ps I respect your option  to do so .

[Guest stevo]

10 minutes ago, Ultrastu said:

I agree with you very much .

And clearly you Also think about your guns and how it works and what it does .

Like most of us here  , I’m always  doing / thinking something shooting related, but not when it comes to shotshells , the only thing I want is consistency. .

 

now reloading for rifles your have my undivided attention forever, many a night I have sat in the back room with my flask of coffee prepping cases  and still do now and then , but that’s different and I 100% agree science has its place ?

Edited December 17, 2017 by stevo

[Ultrastu]

Again I agree. There is a lot less when It comes to shot carts in flight than a bullet or airgunpellet .Take today for example  I shot .gamebore 16 grm no6 plas and layvale 18 grm no6 fibre and layvale 17 grm no5 fibre subsonics 

And they all sounded the same and broke the clays the same .And went in the same direction .I couldn't perceive any difference between them .

[Guest stevo]

2 minutes ago, Ultrastu said:

Again I agree. There is a lot less when It comes to shot carts in flight than a bullet or airgunpellet .Take today for example  I shot .gamebore 16 grm no6 plas and layvale 18 grm no6 fibre and layvale 17 grm no5 fibre subsonics 

And they all sounded the same and broke the clays the same .And went in the same direction .I couldn't perceive any difference between them .

I know what you mean I too , well not so much now days but have used the humble .410 for a lot of my forays. 

I would go out on a limb here and say , ( on clay targets )that the subsonic #5 will have the edge on the other two shells  when it comes to killing at distance . 

Pattern kills . 

[wymberley]

10 hours ago, Ultrastu said:

There is no harm in understanding the science behind shooting it only adds to the enjoyment in my book .

The trigger pulling bit can still be simple and instinctive. 

But the internal / external / terminal ballistics is fascinating 

Being long retired and with time on my hands I enjoy fiddling with the figures. What I think many don't seem to grasp is the advantage of some knowledge. Any shotgun ballistic predicted results are going to vary as thery're based on average findings. Additionally we're faced with initial figures which may or may not be accurate but on which we base any calculations. Consequently, anyone who already has a fair understanding of what's what is well prepared for the field. On the other hand, a complete novice who takes some interest will be able to reduce the time his/her learning curve remains flat and will be on the upward trend far sooner. Yep, all the figures won't put you on the centre spot but at least it gets you in the ballpark enabling one to fine tune the results that much sooner in the field.

[Hamster]

10 hours ago, stevo said:

Hey stu , I’m all for learning but int/ext ballistics with shotshells is nothing more than best guessing .  No two shellsl can be replicated , 

i pattern all my guns for gun fit ( note I said guns NOT shells)  the above rules apply , no two patterns will ever be the same , and to really throw a spanner in the works try shooting though five pattern plates at 5m intervals starting at 20 ,30 , 35 , 40 , 45 yards. The pattern does not just get bigger at constantly changing shape to . So a waste of time .

if you want to talk basic rules of thumb , here’s mine and most of the old farts I have shot with over the past 40 yrs .

a slow cartridge patterns tighter than a fast cartridge , therefore a slower shell tends to hit harder as it’s a denser pattern ( pattern kills )

I packed up shooting live game 18 months ago , after 30 odd yrs of pigeon shooting . I  now shoot fast trap competitively   (ABT , OT, UT )

my comp shells are 28 gram of English 7 , manufacturers say there 1400 FPS  . These pattern tight as there not fast , which when shooting an edge on target at 75-80 mph is a must . I have always felt there is way too much of a trade off when it comes to speed . 

 

One or the other gentlemen .......  you can’t have both . 

Sorry but in clay terms at least this simply isn't born out by either practice or extensive pattern work done here and abroad.

Yes it is true that among the very many established one liners and old wives tales that we have always been told that slow shells pattern better and tighter but unless you go out and try to deliberately load a shell that is so poorly balanced (and fast) that it has the tendency to blow or something they're all much the same, the only real impact is through the shot hardness and wad and of course the type of powder - speed in and of itself is immaterial (within reason) meaning you probably can't get a 1800fps shell to pattern sensibly using current material but even that is prolly doable if there was a need for it.  Manufacturers spend time to balance these things and make sure they pattern well. 

Most top flight loads for clay shooting are going to be a tad faster than what we commonly call "slow" and there is no way you could criticise their tightness, shooters wouldn't use them if they didn't hit hard and smoke clays.  Talking hobbies I have a fair bit of experience of shooting top brands alongside "average" loads, recoil aside there is no question that fancy looking shells pole axe stuff visibly better than slow shells. 

What you have to remember is that at the sort of ranges a typical target is shot the difference between one brand to the next (in delivering number of pellet strikes) is going to come down to things like choke, shot size and ones own accuracy levels. This means that a shooter claiming to be using a "tight" "slow" load in shot size 7 is going to struggle big time to pick out the difference in break signatures between that and say a "fast" number 8 where no claim for tightness is being made. I would happily pay to watch a blind test.