Nice one bucketboy, my mk4 shooting the bis mags shoots well out to 55yard's holds 2Omm in low wind easy , but at 8O yard's opens up to arround 4 inche's think i'll give the jsb heavy's a go and maybe try a leupold 8.5 to 25 mag scope ive got on a 6mm rifle . Ive got an r7 mk1 in .22 may give that a go which of your rifles shoot better at longe range the .177 or the .2O . good looking rifles by the way have you done any internal mods