Got pics of those groups?
They may have clues.
Are your groups round or linear? One group, or two separate
clusters? Two grouping is an easy diagnosis of thing moving. 3 shots aren't going to show much. You need 6 or eight for this to show patterns.
A flat based Sierra or maybe Hornady is what i would try if
you want to see if the thing will shoot. If they won't work,
likely nothing will.
Let's see pics.
