Proving PV 20 was swapped

[Bubo bubo]

PV20 analysis as promised
     
                                   BULLET WEIGHT CALCULATIONS             
                   
                     
A                 B              C = B div by A              D           E = C x D         F         G = F div C 
Grams      Grains       Grains per gram      Weight given     Grains           Grain    Grams 
Eley Data   Eley Data         Ratio             by Taylor gms    per type        weight     per type 
                                                                                                        Pv20     
                     
2.59          40              15.4440                 1.5453           23.865637      26.46   1.713285 
                   
2.27          35              15.4185                 1.5453           23.826211      26.46   1.71612 
                     
1.88          29              15.4255                 1.5453           23.837074      26.46   1.715337931 
                   
2.43          37.5           15.4321                 1.5453           23.847222      26.46   1.714608                   
     
PV20 data 
                                   
1.5453     26.46          17.1229 


                                                  Proving PV20 was swapped.

The figures shown in the table is an analysis of PV20 comparing it to known weight and grain information for all sizes of the .22 hollow point bullet types Ely manufacture. I have created a 37.5 grain type using the averages of the others.

The gram to grain ratio for PV20 should be between 15.4185 and 15.4440. It does not fit with a ratio of 17.1229.

If was weighed by Taylor as 1.5453 grams. It grain weight should be between 23.826211 and 23.865637 grains. It does not compare with a weight by MF of 26.46 grains

If it was 26.46 grains as per MF its gram weight should be between 1.713285 and 1.71612 grams. Once again it does not compare.

The PV20 weighed by Taylor at 1.5453 grams has been swapped by MF because it had incompatible lans and grooves to have been fired by the Anschutz.

Unless the gram to grain ratio changes with fragmentation PV20 is not the same as the fragment weighed by Taylor. It would have to have been swapped.

Grams to grain ratios do vary but are all between 15.41 and 15.44. The ratio for PV20 is 17.122.
I do not know how Jeremy’s ballistics expert (was it Major Mead) verified the bullets. Did he reweigh them? Did he convert grams to grains and vice versa? Did he compare information against GERs and other documents? Also what use did he make of the document which describes PV20 as whole where only the 29 grain figures produce a result which might be considered whole? Even without detailed calculations it would be clear to an expert that 26.46 grains was not a whole bullet.

Mead and particularly Fletcher have a lot of questions to answer
.
The CT need to revisit the ballistics data to check for any other incidents of ‘Jiggery Pokery'
.
You might want to run this past NGB

[mike tesko]

Thank you, very much - your contribution further solidifies the view that I hold, the crime scene bullet (pv/20), was switched/substituted, in order to try and hide from the fact, that the original bullet (pv/20) was not only a different type/kind of a. 22 bullet used in the shootings, but also that the original 'PV/20' was fired via a 2nd,. 22 rifle...

[guest29835]

PV20 analysis as promised
     
                                   BULLET WEIGHT CALCULATIONS             
                   
                     
A                 B              C = B div by A              D           E = C x D         F         G = F div C 
Grams      Grains       Grains per gram      Weight given     Grains           Grain    Grams 
Eley Data   Eley Data         Ratio             by Taylor gms    per type        weight     per type 
                                                                                                        Pv20     
                     
2.59          40              15.4440                 1.5453           23.865637      26.46   1.713285 
                   
2.27          35              15.4185                 1.5453           23.826211      26.46   1.71612 
                     
1.88          29              15.4255                 1.5453           23.837074      26.46   1.715337931 
                   
2.43          37.5           15.4321                 1.5453           23.847222      26.46   1.714608                   
     
PV20 data 
                                   
1.5453     26.46          17.1229 


                                                  Proving PV20 was swapped.

The figures shown in the table is an analysis of PV20 comparing it to known weight and grain information for all sizes of the .22 hollow point bullet types Ely manufacture. I have created a 37.5 grain type using the averages of the others.

The gram to grain ratio for PV20 should be between 15.4185 and 15.4440. It does not fit with a ratio of 17.1229.

If was weighed by Taylor as 1.5453 grams. It grain weight should be between 23.826211 and 23.865637 grains. It does not compare with a weight by MF of 26.46 grains

If it was 26.46 grains as per MF its gram weight should be between 1.713285 and 1.71612 grams. Once again it does not compare.

The PV20 weighed by Taylor at 1.5453 grams has been swapped by MF because it had incompatible lans and grooves to have been fired by the Anschutz.

Unless the gram to grain ratio changes with fragmentation PV20 is not the same as the fragment weighed by Taylor. It would have to have been swapped.

Grams to grain ratios do vary but are all between 15.41 and 15.44. The ratio for PV20 is 17.122.
I do not know how Jeremy’s ballistics expert (was it Major Mead) verified the bullets. Did he reweigh them? Did he convert grams to grains and vice versa? Did he compare information against GERs and other documents? Also what use did he make of the document which describes PV20 as whole where only the 29 grain figures produce a result which might be considered whole? Even without detailed calculations it would be clear to an expert that 26.46 grains was not a whole bullet.

Mead and particularly Fletcher have a lot of questions to answer
.
The CT need to revisit the ballistics data to check for any other incidents of ‘Jiggery Pokery'
.
You might want to run this past NGB

Could you provide a source for your data and explain what other bullets are being referred to? If these are your own calculations, then please tell us where you obtained the data on which you based your calculations. 

Your column C does not make sense to me as mass ratios should be identical.  I suspect the problem is that you, or whoever put the core data together, has rounded-up the imperial mass for each bullet in column B, resulting in a variable mass ratio.  If that were sorted out, then I would expect the mass ratios in column C to be the same.  In both ISU convention and physical reality, 1 gram has to be 15.4323584 grains.  It can't be any other and must always be this, regardless of what happens to any of the bullets.

I agree that the figures in columns A and B for PV20 appear to be out-of-sync, which suggests an issue.  It should be 23.8476234 grains, but unless we know where these figures are from and can see the source, then I'm not sure anybody can usefully comment.

Column D also makes no sense.  You've lost me completely at that point.  The forensic examiner would not come back with the exact same measurement of mass for every bullet.

[Bubo bubo]

I am sorry you are struggling with this. The sources of the data are clearly shown Columns A  and B are what is stated by the manufacturer. Column C is a spread sheet calculation based on A & B as stated. Column D is the gram weight given by Taylor on the GER. Column E is as stated. Column F is the grain weight given by MF. Some columns contain the same data because I am comparing all the various sizes of hollow point manufactured by Ely in order to see if there was any match against all the available sizes.

I have had this checked and was told that my calculations were valid.

I think I have set this out clearly you are the first to call it in to question so others do not care or are happy with the information I have provided.

[guest29835]

I'm struggling with it because you are not making yourself clear and your table doesn't make any sense to me mathematically. 

If I'm not clear, then others will not be clear, but maybe are too proud to speak up and ask.

I am asking you to provide your source document or link to the document or tell us what document you have seen so we can find it.  It's just convention.

As to what you are trying to do here, I have to read between the lines, as you're not being clear.  I think what you're saying is that you have transposed the mass recorded for PV20 to columns D and F and multiplied the imperial mass by the varying mass ratios in the hope of finding a bullet that matches the recorded measurements for PV20.

The problem, as I have explained, is that column C is wrong because the mass ratios can't vary.  This means the whole exercise is misconceived.  Column C must always be the same figure common to all bullets.  This means that in column C you are always multiplying by 15.4323584, which in turn means that the product in column G for any bullet will only be the same as PV20 if that bullet has the same mass as PV20 in the first place, which should be self-evident from the source data anyway.

I have had this checked and was told that my calculations were valid.

So what?

I think I have set this out clearly you are the first to call it in to question so others do not care or are happy with the information I have provided.

Irrelevant.  If I don't understand something, I will speak up.  I also check things and don't make assumptions.  I check sources for claims and I always want to know who has verified what.

[Bubo bubo]

I fully understand your predicament. I believe the data came from an historical leaflet/magazine posted on this site or from a website from at least 8 years ago. There were arguments at that time about using information from 1985. I did not want to be accused of manipulating the data for my own ends. It was definitely an Ely document. I guess they use a rounding process when displaying gram and grain weights for users. The variation in results of calculating mass is minor.

In order to settle your mind I have redone the calculations using 15.4323584.

on this basis a grain weight given by MF translates to 1.714579153 grams But Taylor weighed it at 1.5453

Similarly 1.5453 grams translates to 23.84762344 grains but MF weighed it at 26.46 grains

PV20 has been swapped which ever way you cut it. Happy now?

This produces a grain to gram ratio 13.90873 not 15.4323584.

[guest29835]

I fully understand your predicament. I believe the data came from an historical leaflet/magazine posted on this site or from a website from at least 8 years ago. There were arguments at that time about using information from 1985. I did not want to be accused of manipulating the data for my own ends. It was definitely an Ely document. I guess they use a rounding process when displaying gram and grain weights for users. The variation in results of calculating mass is minor.

In order to settle your mind I have redone the calculations using 15.4323584.

on this basis a grain weight given by MF translates to 1.714579153 grams But Taylor weighed it at 1.5453

Similarly 1.5453 grams translates to 23.84762344 grains but MF weighed it at 26.46 grains

PV20 has been swapped which ever way you cut it. Happy now?

This produces a grain to gram ratio 13.90873 not 15.4323584.

The crucial point is the bit above emboldened.  I don't know what your source is for Fletcher's measurements, but for the purposes of this discussion, let's take your data at face value and go from there.

I assume it must have been FSS procedure to take two measurements for completeness: one imperial, one metric.  The question is: Why is the recorded imperial measurement of mass inconsistent with the metric measurement for the same bullet?  The laws of physics tell us that the mass ratio is constant and so the measurements have to be consistent to the ratio.

The answer to the question is complex because before we jump into exploring malevolent motives, we first have to consider the possibility of mistake: specifically, in this case, the problem of calibration.  One troy grain is significantly less than a gram.  A gram is roughly the mass of a paperclip.  It's not difficult to see how a mistake could be made, but the likelihood of a calibration error, or even a simple human
error in measuring, depends on the measuring instruments used. 

We need to see your documentary sources and we need to see when the two measurements were taken, what record Fletcher and Taylor made of the instruments they used, how they used them, and how they calibrated these measuring instruments.

[Bubo bubo]

You are now posing arguments you know I cant possibly answer. You have lost the argument and are resorting to suggestions of calibration problems and human error. The Taylor weight is given on a GER which should be available on the forum and so is the MF data. Additionally there is a photo of PV20 with the weight beside it.
Please do not continue a pointless argument in order to show that I am wrong. I will not be responding to any more arguments on this subject. PV20 was swapped as far as I am concerned and I am happy for others to decide who is right and who is wrong. Your behaviour will needless be taken into account when they make their decisions.

I do not know what they ate for breakfast that morning any more than I can know what instruments were in use at the FSS nearly four decades ago. I thought you better than this.

[guest29835]

You are now posing arguments you know I cant possibly answer. You have lost the argument and are resorting to suggestions of calibration problems and human error.

What..?  I'm doing nothing of the kind.  Why are you flying off the handle?  It's the second time this has happened.  I'm not taking issue with you.  I'm just trying to understand your posts.  I haven't 'lost' any argument.  We haven't had an argument.

The Taylor weight is given on a GER which should be available on the forum and so is the MF data. Additionally there is a photo of PV20 with the weight beside it.  Please do not continue a pointless argument in order to show that I am wrong. I will not be responding to any more arguments on this subject.

It is very reasonable for me to ask you to back up your data with sources.  This is standard academic practice.  Whenever I make sourceable claims, I back it up with references or links.  If you don't want to do so, that is your business, but you shouldn't be surprised that I am asking you to do so.

It is also entirely up to you whether you want to respond to posts, but take note that when you post here, I and all other members are entitled to constructively critique and comment on your posts.  That is what a Forum is for.  If you won't tolerate this, then you belong elsewhere.

PV20 was swapped as far as I am concerned and I am happy for others to decide who is right and who is wrong. Your behaviour will needless be taken into account when they make their decisions.

What behaviour?  All I have done is attempt to engage in a normal, sensible dialogue about your ideas.

I do not know what they ate for breakfast that morning any more than I can know what instruments were in use at the FSS nearly four decades ago. I thought you better than this.

Not true.  When people take scientific measurements, they are supposed to record the instruments they used and the calibration procedures undertaken.  This is nothing more than conventional method in a range of industries, and I know for a fact it is also the case in forensic science.  Instrument interrogation is every bit as important as the findings and it is supposed to be done and recorded.  I say 'supposed to' because they won't always, and I don't know if it happened here. 

Calibration and human error are very relevant considerations before we jump off the deep end accusing people of malpractice.  My experience is in the railways, construction and renovation industries.  Among other things, I have been a track inspector and a site manager.  Instrument calibration is fundamental and anybody who doesn't understand it will quickly fall into error and incompetence.  A simple tape measure, for instance, is actually quite a difficult tool to use in the wrong hands. 

I recommend you take a breather from the Forum now and come back in a few days.   My comments are polite and constructive and I have not in any way insulted you.  I do look for flaws and faults in others' reasoning because this is necessary in order to test ideas and develop a full understanding of things. There is no reason for you to take any of this to heart. 

[Bubo bubo]

I will not take instruction from you. I am perfectly capable of ploughing my own furrow and will proceed as I see fit. I have not accused you of insulting me where did I say that? You know there are limitations to what is achievable in pure academic terms when dealing with such a complex issue with limited access to all the data required to make a truly definitive article/case. This is not an academic arena and while we may wish to test each others arguments in an academic fashion we can end up asking for things we cannot know or reasonably expect to be provided. I take the view that if people are truly interested in a particular argument they will seek for themselves as to whether to trust or believe what a poster says and come to their own conclusions.
We must accept the environment in which we are working.
I find some of what you say patronising and do not like such a tone.
Given the importance and other issues surrounding this item I believe it reasonable to deduce that it was swapped. It certainly did not shatter into at least 15 pieces as shown in an Xray.
You are quite entitled to question what I say but it seems to me that you are now attempting to take the moral high ground by requiring me to provide information which you know I cannot produce.
Like I say it is for others to decide

[Bubo bubo]

Here is the Taylor GER. I will post the picture tomorrow if I have time

[guest29835]

I will not take instruction from you. I am perfectly capable of ploughing my own furrow and will proceed as I see fit. I have not accused you of insulting me where did I say that? You know there are limitations to what is achievable in pure academic terms when dealing with such a complex issue with limited access to all the data required to make a truly definitive article/case. This is not an academic arena and while we may wish to test each others arguments in an academic fashion we can end up asking for things we cannot know or reasonably expect to be provided. I take the view that if people are truly interested in a particular argument they will seek for themselves as to whether to trust or believe what a poster says and come to their own conclusions.
We must accept the environment in which we are working.
I find some of what you say patronising and do not like such a tone.
Given the importance and other issues surrounding this item I believe it reasonable to deduce that it was swapped. It certainly did not shatter into at least 15 pieces as shown in an Xray.
You are quite entitled to question what I say but it seems to me that you are now attempting to take the moral high ground by requiring me to provide information which you know I cannot produce.
Like I say it is for others to decide

I am not requiring information.  I am in no position to do so.  I am merely asking for it.  You can choose to or not to.  You can also choose to reply or respond, or to give no response at all and ignore me.

Whether you like taking 'instruction' (as you call it) from me or not, this is a public Forum and I am a member, and I am entitled under the terms of membership to comment on and critique your posts, as long as I am constructive, polite and civil in going about it.

I would say that, so far in our exchanges (not just here but on other threads) the only person who has been less than constructive, polite and civil is yourself.  You are the one in the wrong.  This Forum has rules.  You can't launch personal attacks on me just because you don't like constructive criticism.  This is important because I need to be reassured when I come on here that I can comment on your posts without you turning round and attacking me, as you have now done here.

I could understand your posts if I had insulted you or goaded you in some way.  I really haven't.  There is no defence for your behaviour here and I really recommend that you take a breather from posting for a while.

[guest29835]

Here is the Taylor GER. I will post the picture tomorrow if I have time

I appreciate that, but the atmosphere is soured now because you have created this completely unnecessary drama over very ordinary posts.  You could have just attached whatever documents, or just said you don't want to and I should find them myself.  I'm genuinely baffled by your personal attacks on me. 

Instead of coming back tomorrow with more attachments, I would stress to you the importance of taking a break.

Apart from that, the document you have attached, while obviously of interest in that it confirms the metric mass of PV20, isn't the one that addresses the key point.  You're saying that Fletcher measured PV20 at 26.46 grains, so I would be interested to see the document that states that, especially if it also shows what measuring instruments he was using. 

Also, the document is giving the 'weight' (should say mass) of PV20 after it is 'spent'.  We know from the notes of Vanezis that the bullet was fragmented.  This leads me to ask: What is the mass in the Eley data for that type of bullet?

[mike tesko]

I believe that I am correct in saying, if my memory serves me correctly, the the defence ballistic expert, 'Major Mead' took this photograph, he took 'it' sometime after the prosecutions ballistic expert, 'Malcom Fletcher' described exhibit 'PV/20' as 'a whole bullet' in his witness statement...

'Major Meads' , photograph of 'crime scene bullet' , exhibit 'PV/20'..

[guest29835]

That says 26.46 grains.  Was that put together by Mead or did he simply photograph what he found?  Did he take photographs of the other spent bullets in a similar way?