Bob,
The 0.22" pellets I have weighed ( in lots of 100) are :
Air Arms Diablo Field - Stated 16 gr., actual average 15.9 gr., (heaviest - lowest = 0.5 gr.)
JSB Jumbo RS - Stated 13.4 gr., actual average 13.4 gr., (heaviest - lowest = 0.5 gr.)
JSB Jumbo Express - Stated 14.4 gr., actual average 14.3 gr., (heaviest - lowest = 0.5 gr.)
JSB Jumbo Exact - Stated 15.9 gr., actual average 15.9 gr., (heaviest - lowest = 0.7 gr.)
(The results are in the spreadsheet I sent you.)
I have still not heard back from JSB with regards to their 'optimistic' weight tolerance claim for their Premium line of pellets - they state +/- 1 mg., I found spreads of 6 to 7 mg.
Have fun
Best regards
Russ