JSB / Air Arms Die Numbers and Dates

An interesting question flashed across my desk a few days ago, and after doing some reading up I found some useful tips when trying to decipher the die numbers and dates found on the back of Air Arms and JSB pellet tins. 

JSB tins have three numbers:
First Number: 45160015
Second Number: 2
Third Number: 4.52

The first number is broken down into the following:

  • 45 (The number of the pressing die that was used to make the pellets)
  • 16 (Production Employee ID)
  • 00 (Quality Control Employee ID)
  • 15 (Year of production)

This makes it very easy to identify the die and year of production by looking at the first and last two characters of the long number. This is also accompanied by 2 (manufacturing batch number) and then 4.52 (the calibre)


Air Arms are a little more straightforward and separate the numerics

  • 6 (The number of the pressing die that was used to make the pellets.)
  • 25.09.2018 (Date of production)
  • 4,52 (Calibre)
  • S4 (Manufacturing batch number)
  • 54 (Quality Control Employee ID)


If you're a user of either of these brands, it's worth recording changes in group sizing and placement if you use pellets from a different die and date, alongside your existing shot data. Each die may vary slightly, which will in turn vary the accuracy and consistency of shot placement. Just like pellet size however, your individual rifle barrel will respond differently, so what might work well for one rifle may perform poorly in another and vice versa.

You can find Air Arms and JSB pellets on our website, along with our Pellet Database which contains weight and velocity information where possible.

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