Her er svaret fra Eley
Dear Roy
Regarding the folder received from one hunter in Norway complaining about the performance and mainly the quality of the components used in some of our bismuth cartridges, and after meticulously analyzing this data, we are sending you the following conclusions.
Together with the conclusions, we think that it is very important to know the nature of the bismuth itself, the performance as a raw material, the difficulties (sometimes impossibilities) in the manufacturing process of the shot and its differences with lead and another non toxic materials.
Bismuth is considered the best alternative to lead as cartridges shot, because of its density, hardness, etc… but we cannot expect a bismuth pellet to look as round as a steel or lead pellet.
Bismuth is melted to be processed for making the pellets, either through a Collins system or injection molded and in contrary with other metals, bismuth expands when gets cooler. This expansion is uncontrollable, so we cannot control in which shape it is going to expand, that is the reason why not all the pellets are perfectly rounded and not all of them weight the same.
Another characteristic of the bismuth is its fragility. This fragility is partially controlled with a special alloy; a small little change in the alloy (one percent difference) changes the optimal specification and it becomes more fragile than expected. This fragility may cause pellets break when hitting the target.
Conclusions:
1.- Powder.
In principal, you have to load a lot of cartridges according to the ballistic specifications of every lot of powder. Every lot of powder have different ballistics due to many reasons and you have to adapt your load to this specifications in order to achieve the same ballistics for this cartridge regardless the lot of powder used, so sometimes you have to put more or less.
In your report, for the same lots, the differences a minimal, and of course all within tolerance, average 0,024 grams.
2.- Pellets.
In number of pellets, there is a maximum of 9 pellets in a number 4 and minimum of 2 pellets in a number 5, way within tolerance.
Regarding the shot size and due to the fact of the irregular shape as explain before, the way we measure the pellets is as following: we take 20 pellets and put them inside a ruler and take the average diameter in millimeters (see photo attached).
Roy, the final conclusion is that the cartridges are, to say, very, very well loaded, with minimal differences that will NEVER affect the performance of the cartridge.
The only points that apparently the hunter could argue about belong to the nature of the bismuth, and this is something that we cannot change. As explain before, we can try to avoid some things to happen, but not to change the natural characteristics of this metal, which actually makes it the best alternative to lead.
Please find attached a small summary of the report received from you.
Should you have any further question or require further information on this question, please do not hesitate to contact us.
Many thanks again and best regards.
José M. Marcet