Mine will shoot 1/2" 3 round groups, but count the other 2 and it opens up to 1&1/4";(100yrds) this seems to be consistant. I have added a free float tube and RRA 2 stage trigger and mostly just use reloads.
I suggest get a couple of different brands of ammo and give it a try.
Like most everything you can buy, ya get what ya pay for.
I think the Oracle is a nice rifle for a cheaper entry level AR; I guess it would be asking quite a bit for a light weight 16" pencil barrel to shoot as accurately as the 20" Bull SS.
