My testing results
Whilst waiting for JSB to test the samples I sent (although initial inspection results are available as above), I have been testing the two batches of pellets for myself, with some interesting results, here they are :-
The first thing I did was to make a cradle to firmly hold my rifle in position and steady, all the results below have been gained using this system. The two batches are refered to as "batch 1" 020-1303-4.52-68 (known to be good) and "batch 2" 260-3010-4.52-58 (new batch with problems)
Tests under "very very" still conditions and outside at 55 yards
Batch 1 pellets (good) 10 shots group to 9mm ctrs (centre to centre) exactly on the aiming point.
Batch 2 pellets (suspect) 10 shots group to 18mm ctrs but the group is centred at 29mm below the batch 1 group
Tests with windy conditions (steady wind at 6 mph, exactly at 90 deg's to pellet flight R-L) at 55 yards
Batch 1 pellets (good) 10 shots group to 17mm and are ofset from the aiming point by 39mm to left
Batch 2 pellets (suspect) 10 shots group to 58mm and are offset from the aiming point by 64mm to left and 35mm below.
I was a little concerned with the above results, that something may have changed, so retested the pellets by alternating the pellets and shooting one of batch 1, then 1 of batch 2, etc, etc, instead of all 10 of each batch at a time, the results were within a millimetre of the above quoted figures.
Batch 2 (suspect) pellets are appear to be very unpredictable in windy conditions and "take" much more wind than batch 1 pellets, but in still conditions they do group to 18mm ctrs at 55 yds (allbeit at 29mm below to aiming point).
This is only my personal opinion but, I belive that it is mainly the C of G position that is causing the problems and it is the manufacturer (JSB) who should be ensuring that the C of G of the pellets is in the correct position thus negating most of the problems of inconsistancy as above.
I wonder if we can get JSB to ensure that the C of G of their pellets, (at least competition pellets) is correct and consistantly correct to the design specifications.
Please forgive me for rattling on and on chaps !!