Chrono test results - Daystate Prestige .177 X2

[Balotelli]

3 hours ago, Ultrastu said:

No .lead is not lead .

Lead used in pellets usually has antimony added to it to make  it harder .

Pure lead is very soft and if used will deform badly in manufacture and transit and even irregularly upon firing .

So antimony makes it harder and more consistent. But this hardness can have a down side .it can make bore friction greater robbing the pellet as it flies down the barrel of energy .

Jsb tend to make a soft pellet with thin skirts which balloon (the skirt ) well in the barrel making a tight bore fit this reduces air blow past allowing for an increase in velocity .(the down side is bent pellets in the tin  and hence the sponges in the tins ) 

Rws add a lot of antimony. And I've yet to see a deformed rws pellet in a tin in 30 years of shooting  .

Thanks.  A lot of info here and in your following post, that I had no clue about. It would seem that you are somewhat of a guru on airguns and related issues. In future, I'll ask you what pellets to use in my PCPs although it looks as though RWS might be a good bet. Maybe there's a happy medium between hardness of the pellet and thinner skirts with a corresponding tighter fit and hence velocity. I was under the impression that there were only a handful of pellet makers in the World- having said that, I guess that there is nothing stopping a brand asking for a pellet maker to use a particular composition.

[wymberley]

13 hours ago, Mice! said:

This is the instructions for my chrono, sorry thought I'd put this on.

We're all singing the same hymn, it's just that the SI Unit value for a slug was amended a while back -  so some of your info' is dated which will make little difference to your calculations but might just be confusing if you see something more recent - and is now 32.174

[London Best]

2 minutes ago, wymberley said:

We're all singing the same hymn, it's just that the SI Unit value for a slug was amended a while back -  so some of your info' is dated which will make little difference to your calculations but might just be confusing if you see something more recent - and is now 32.174

I understand what you are saying, and appreciate the information, of which I was not aware. But basically I don’t understand how anyone has the authority to change the value of gravity?

[wymberley]

13 minutes ago, London Best said:

I understand what you are saying, and appreciate the information, of which I was not aware. But basically I don’t understand how anyone has the authority to change the value of gravity?

Not a clue - I'm afraid you'd have to ask the Systeme International (d'unites), but I think it was more of an international standard agreement more than a change as as you're aware the figure can vary dependent upon where you are on Earth

[London Best]

1 minute ago, wymberley said:

Not a clue - I'm afraid you'd have to ask the Systeme International (d'unites), but I think it was more of an international standard agreement more than a change as as you're aware the figure can vary dependent upon where you are on Earth

Let’s just blame the EU!

[wymberley]

5 minutes ago, London Best said:

Let’s just blame the EU!

[Mice!]

2 hours ago, wymberley said:

We're all singing the same hymn, it's just that the SI Unit value for a slug was amended a while back -  so some of your info' is dated which will make little difference to your calculations but might just be confusing if you see something more recent - and is now 32.174

20 odd years old my chrono, I just put the pellet weight in and fire off a few shots,  gives me the fps so I can see the spread and tells me I'm under the 12 .