Shooting accuracy and wounding

caorach

Well-Known Member
I got this from the BASC email listing recent scientific papers of interest to stalkers

PLOS ONE: Factors Associated with Shooting Accuracy and Wounding Rate of Four Managed Wild Deer Species in the UK, Based on Anonymous Field Records from Deer Stalkers

One section that will certainly cause debate, just to stir things up a little and get a little interest in what looks to be useful research, will be this:

For Bullet weight, the poor performance of bullets under 75 grains warranted further investigation to establish whether bullet weight or rifle calibre was driving the result. The original data showed that 54 shots from five stalkers involved bullets weighing less than 75 grains. Two of the shots were fired from a high-velocity Remington 22–250 rifle, and both shots killed their targets. The remaining 52 shots were fired from rifles of calibre.222,.243 or 6 mm, with muzzle energy below 2000 J. All were fired at roe deer and 17.3% of these shots resulted in wounding. There was no obvious effect of distance, as only one of the wounding shots extended beyond 100 m. Three of the same stalkers also fired 22 shots at roe deer from rifles of identical calibre using bullets weighing over 75 grains (muzzle energy above 2500 J): there was no incidence of wounding. For comparison, another 37 stalkers fired 440 shots at roe deer from rifles of identical calibre using bullets over 75 grains: the wounding rate was 4.5%.
 
Does this mean that shooters with more experience choose more suitable bullets?

Did, for example, the 3 shooters who used bullets of weights below and above 75 grains move to the heavier weights because they weren't satisfied with the performance of the lighter bullets they had used previously?

There are of course bullets that are designed to give controlled expansion with a high degree of weight retention in the sub-75-grain category, but the vast majority of .22 and 6mm bullets under 75-grains are "varmint" bullets designed for rapid expansion/fragmentation. If these were chosen for use on roe deer I can see why wounding might result.

Shops tend to stock such bullets for the smaller calibres since most are used for foxes, small game and vermin, and most shooters who begin their rifle-shooting careers pursuing such quarry naturally buy and become familiar with them. Do these shooters then go on, having had the necessary condition added to their certificates, to use them on deer, and do they only seek out a better bullet after one or more animals have run off?

BTW I'm assuming that wounding meant that a second shot was deemed necessary or that the animal showed signs of being hit but was never recovered, but will go off and read the paper in question to check their definition.
 
Is that why the FC ask for .270 or above for Lamping deer by contractors. Looks like the little bullets need to be driven in to the exact poa
 
Well I for one will be sticking with my "useless, wounding, sub 75gr" .222 soft points in 60gr form for roe

not had a wounding or a runner yet!

stick any bullet in the wrong place and you will wound
make it worse with the wrong construction and you will increase your chances of a wounding
 
I wonder if those using 22/250,s or 222,s had started off as fox shooters ? Small targets require better accuracy. Also those calibres offer very little recoil.
 
Is that why the FC ask for .270 or above for Lamping deer by contractors. Looks like the little bullets need to be driven in to the exact poa

FFS why does every thread you reply to need to involve the FC. You were boring before but now you are really boring. Change the record

Al
 
Caorach did the report take into account the type of bullet used as Mr Gain makes a very valid point about bullet selection and suitability?
 
I wonder if those using 22/250,s or 222,s had started off as fox shooters ? Small targets require better accuracy. Also those calibres offer very little recoil.

I think that's a very valid point. In my post I didn't mean to imply that fox/vermin shooters were any less accurate when shooting at deer, only that they might unwittingly make a poor choice of bullet by sticking to what they know.
 
Is that why the FC ask for .270 or above for Lamping deer by contractors. Looks like the little bullets need to be driven in to the exact poa



Using the site to pursue personal vendettas, stirring up trouble seemingly for one's own amusement and relentless general unpleasantness is unnecessary, it spoils the site for the majority and it won't be tolerated. Accounts being used for this purpose will be suspended.:

...
 
FFS why does every thread you reply to need to involve the FC. You were boring before but now you are really boring. Change the record

Al

I am sure this would be relevant R22 FC made a educated choice to use bigger harder hitting rounds because the small calibres were not up to the job eg (.243 ). I am not sure if they didn't an official study but it did show they were worried. Also with deer welfare being the top of the list when deciding competence I am sure this will come into the equation.
 
Caorach did the report take into account the type of bullet used as Mr Gain makes a very valid point about bullet selection and suitability?

Read the whole paper, it is well worth reading as it highlights just what they did take into account. They do highlight that all deer were shot using expanding, deer legal bullets. Beyond that you can say no more.

What is also interesting is the, very short, discussion of wounding rates on whitetail deer in the USA and how much higher they are than the UK rates. I would guess this is down to our culture of using sticks and rests and so on over freehand shooting.

Again credit has to go to BASC for bringing this to our attention.
 
Is that why the FC ask for .270 or above for Lamping deer by contractors. Looks like the little bullets need to be driven in to the exact poa

I'm sure that's exactly why. Not only is it a decent size, hard hitting bullet, it is fast and flat which will be more forgiving with poor range estimation which can easily happen at low light.
I also believe that shoulder shots are deemed better in such circumstances which requires a good bit of penetration to ensure a humane result.
MS
 
Read the whole paper, it is well worth reading as it highlights just what they did take into account. They do highlight that all deer were shot using expanding, deer legal bullets. Beyond that you can say no more.

What is also interesting is the, very short, discussion of wounding rates on whitetail deer in the USA and how much higher they are than the UK rates. I would guess this is down to our culture of using sticks and rests and so on over freehand shooting.

Again credit has to go to BASC for bringing this to our attention.

I admit that so far I have only skim read it. :oops:

I think that it would be very difficult to make valid comparisons with the U.S. for a number of reasons from what I have read not from experience as I have never shot over there. Perhaps a better comparison could possibly be made with several European countries where .22 centrefires are often used to stalk roe deer, after all most of the methods that we currently use in this country have been brought back from the likes of post war Germany, discounting driven shooting of course.
 
So I have read this and I see some fundamental flaws in the conclusions drawn from the assumptions made and the preparation of data for analysis.

"we derived 28potential explanatory variables"
"Because stalkers did not always complete every field on theforms, there were missing values in many of the variables(Table 1). Overall, only 1325 data records out of 2281 containedno missing values (Dataset S1). This meant that for a joint analysisinvolving all explanatory variables, an approach that consideredonly records with no missing values would reject 42% of thedataset. We considered this extent of data loss to be unacceptable,so we replaced missing values for a given variable using nonmissingvalues from other records chosen at random from a list ofsuitable matches"

So basically for over half of the forms that were returned some data was missing
That data was added by the researchers based on data from the other forms.


Ten variables were identified as being significantly associated with the probability of a shot hitting its target (Table 3; Figure 1). None of the two-way interactions among these variables was significant. (Except time and distance! below)

Distance to target (Figure 2C, 2D).
The statistical interaction between distance and time available arose because there was no detectable effect of distance on the probability of a hit animal being killed when there was sufficient or more than enough time

Distance to target (Figure 1C).
The probability of a shot hitting its target declined increasingly with distance, from 95% (distances under 75 m) to 91% (distances of 75–149 m) then 83% (distances of 150+ m). The relationship was linear on the logistic scale, and when distance was considered as a continuous variable the slope was 20.010, giving the relationship P(hit) = 57/(57+e 0.010 distance).


So despite there being less chance of hitting an animal the further away it was the animal was just as likely to die if the shooter had enough time for the longer shot?
Am I missing something here?!?

and this then seems to contradict those facts:

"The two probabilities, that a shot hit a target deer, and that it killed a deer that was hit, were associated with a set of ten and seven variables respectively that explained significant amounts of variation. Three variables were common to both sets, namely the comfort of the shooting position, the distance to the target and the time available for the shot.

"For Bullet weight, the poor performance of bullets under 75grains warranted further investigation to establish whether bulletweight or rifle calibre was driving the result. The original datashowed that 54 shots from five stalkers involved bullets weighingless than 75 grains. Two of the shots were fired from a highvelocityRemington 22–250 rifle, and both shots killed theirtargets. The remaining 52 shots were fired from rifles ofcalibre.222,.243 or 6 mm, with muzzle energy below 2000 J. Allwere fired at roe deer and 17.3% of these shots resulted inwounding. There was no obvious effect of distance, as only one ofthe wounding shots extended beyond 100 m"

Simple physics dictates that the energy delivered into a target is less the slower they are travelling.
Distance has a linear effect on this and subsequently can not be discounted.
Muzzle energy doesn't kill deer.
Moreover, a sample of 54 shots from a overall sample size of 2179 is not significant enough to draw a conclusion on bullet weight from without assessing the other significant factors involved.

No indication of what target size they consider a "Hit" or what was being aimed at compared to where bullet hit.
Chest is awfully big and if you are counting anything between C7 Neck joint and the diaphragm as a "hit" then it will skew results
Account for poor target choice and operator error

No indication on rifle/shooter capabilities
rifle test for all shooters before and comparative results in field
Account for operator error

No indication of range vs MV to extrapolate Impact Energy/Velocity over MV
Account for assumptions on bullet/calibre choice


"Conclusion:
(a) Choose a comfortable shooting position. - Basic advice -
reduce margin of error
(b) Avoid shooting off elbows or freehand, use a support (e.g. sticks, bipod).
reduce margin of error
(c) Aim at the chest or lower neck. - reduce margin of error
(d) Use bullets heavier than 75 grains. - no indication of velocity or calibre or bullet type
(e) Avoid shooting when there is insufficient time. - reduce shooter error
(f) Shoot a distant animal only if there is sufficient time. - This I would argue, time does not evade physics.
(g) Shoot an animal when it is stationary.
reduce margin of error
(h) Avoid shooting an animal that is heavily obscured or in thicket. -
reduce margin of error
(i) Take extra care when the ground is not well known. - This I do not understand. how does this kill deer more effectively?
(j) Carry out shooting practice at least once a month" -
reduce margin of error



Doesn't compel me to change my rifle or bullet choice I am afraid
 
I am sure this would be relevant R22 FC made a educated choice to use bigger harder hitting rounds because the small calibres were not up to the job eg (.243 ). I am not sure if they didn't an official study but it did show they were worried. Also with deer welfare being the top of the list when deciding competence I am sure this will come into the equation.[/QUOTE

But is there any need to bring the FC into your posts every opportunity you get ? You are spoiling threads which otherwise would be an interesting read.

Al
 
R22 It should be taken as a compliment FCS shoot more deer than any other organisation and most if not all of there major discussions are made on scientific facts and findings. So if they say that smaller calibres are not really suitable in certain circumstances then people will listen. If Joe public suggests it then normally it would have limited credibility.
So I feel that FCS and SNH being the two major deciders on deer related matters then there finds are worth a mention.
The are currently supporting a copper bullet study all relevant to this type of thread.
 
Having read this semi-thoroughly, I would say this:

1. Had I been the referee, I would have rejected the paper on statistical grounds and asked them to resubmit having cleaned up their analysis.
2. Having said this, I think most, if not all, of their conclusions are uncontroversial.
3. More broadly, I think we should encourage a more rigorous, evidence based approach to what we do - and be open and supportive of attempts to do it.

The only conclusion which seems remotely controversial is the <75gr one. Looking at the data, this is really just an artefact of sample size, and is likely to be strongly confounded with a number of other variables (such as species type and vegetation cover).
 
So I have read this and I see some fundamental flaws in the conclusions drawn from the assumptions made and the preparation of data for analysis.
Thankyou for getting stuck into this.

I am absolutely no statistician, but prima facie it does seem that the "headline" figures are not as accurate as they have been presented. The fact that the recommendations seem only loosely related to the statistical anaysis is also open to criticism.
 
There are two main weaknesses to this study.

First, if it is trying to shed light on the non-human factors influencing shot efficacy (e.g. bullet weight, velocity, shooting position, aim point or deer behaviour) then considering the shots of 102 stalkers introduces a large degree of 'operator error'. On average, each stalker would have contributed just 2281/102 = ~22 shots to the analysis. These shots will all have differed greatly in their firing point position and deer behaviour etc, but are unlikely to have differed much in their bullet weight or calibre used (few stalkers will normally use a vast number of rifles/bullet mixes). What makes this even harder to understand and hence control for is that although 22 shots was a mean, the range was very large (1-72 shots per stalker). Whilst the modelling approach to some extent controls for this statistically, a better approach would have been to select a small(er) number of well trained :stir: stalkers who would be specifically asked to shoot a range of bullets/calibres/species. This would have allowed the analysis to tease apart operator error from ballistic efficacy.

Second, quite a few of the variables were subjective AND assigned retrospectively. The factor 'Were you comfortable and stable?' - I imagine that if the deer was killed immediately, you may well answer 'yes' despite being in exactly the same position as an occasion where for some other reason the deer was not killed outright and the stalker retrospectively tries to explain the miss. This is not suggesting that the stalkers were deliberately lying, but rather we all have confirmation bias which can depend on our success or failure. Such problems could apply to the variables comfort, time available for shot, light, concealment, and alert state. Three of these measures (comfort, time and concealment) all contribute to explaining the model. It would have been better (although I accept perhaps less practical) for the stalker to collect these data immediately prior to the shot - I imagine tapping answers into a mobile phone lying in a deep peat hagg in driving mist:D

The study is an interesting first attempt to explore the efficacy of deer shooting under field conditions, and given the provenance of the authors, I doubt they are trying to cause trouble to stalkers. This is not a paper to reject or ignore, but rather one to spark additional further (and perhaps better focussed) research.
 
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