i am using jsb match diabolo exact diabolo batch number 40007310 ( 4.52 ).
& at funace mill they are great to 55 yards, as i have a zero at 35 yards & can get pellet on pellet if not pellet in pellet on a nice day.
however at 55 yard i can get 1/2 " most of the time & if the wind is picking up its the same really however at 55 yards some times the group is 1 to 2 "
my fault as i need to train & train.
i can get a bit better groups using daystates ft 4.52 & 4.51's but they have flyers what the above have little if any !!.
i am not a top shooter but i am getting there
, just letting you know & if i had a indoor range & that i would be glad to help you out.
but i also think you need some out door tests too, as that is where most users would use them in real life.