Hello. I have a Leshiy 2 .177 FAC with an Alpha Precision barrel. I'm having a hard time getting it to group well. I´m using ZAN 13g and KO 13.43g. I've tried jets/nozzles ranging from 0.8 to 2.0 and different regulator pressures. I've shot at speeds from 850 to 1050 fps, but it won't group and produces many/few flyers. Is there anyone with experience using Leshiy 2 and slugs in .177 who can provide some insights?