Can't believe I missed this thread, before. I've been wanting to see some reviews and range reports on the American.
It's good to see that it's performing well.
If you have any more problems with those rings, pick up a set of the Weaver "Grand Slam" rings (and make sure the bases are tight, of course). The Grand Slam rings look pretty decent, and have treated me better than any other brand of weaver-style rings (including "premium" brands like Leupold). As a bonus... they're on sale quite often.
Speaking of which.... I used my last set of "spare" weaver-style rings on a new rifle, earlier this year. Time to keep an out for the Grand Slams to go on sale.