Just checked my new TC Impact and can't feel anything loose in the hinge pin when I wiggle it side to side.
Are you getting play from side to side? I haven't broke mine down yet, but the manual shows how to remove the barreled action from the stock, maybe start there to see what it looks like. Maybe you recieved an undersized hinge pin or an oversized mounting hole or both.
Do you have a scope mounted on the rifle?
I am only shooting a light charge of powder so far, 60 grains of BH 209. We were practicing for my 9 yr olds first deer hunt and shooting small green tomatoes off the target at 50 yards with a 250 grain TC shockwave bullet with the supplied black sabots. Accuracy has been very good.
The trigger on ours is good, only slightly more weight than my son's Triumph which is a very nice trigger.