Hi all,I have had a tikka tac a1 for a little over a year now.since i do not reload i found hornady 147 eld works great.sub .5 moa all day with some .25 groups.following tikka’s reccomandation and i find cleaning the rifle after every range trip works best.about 600 rds through it now and out of the blue it has become very inconsistant.it shoots 2 sub .50 groups,then one or two 1.5 groups(see pics below).i have had 2 good shooters try it with same results,although it loves the 147 eld,i tried 4 other ammo’s,i made sure the recoil lug is seated and also tried tightening the receiver bolts from 35 lbs to 62lbs(tikka recc)in 5lb intervals.i removed the optic and remounted(athlon cronus & seekins rings)i am out of ideas and would appreciate any input or ideas,thanks all