They look durable enough and I haven't crunched mine, but I'm not THRILLED with them either. I got a little fine dust in one while hunting and it crapped out for a little bit, wouldn't feed any rounds. Not sure how it happened, but it did.
I'd buy another one since they're super light and accurate as can be. But, if I had my choice I'd rather have a traditional box mag like the Rem 783.
In terms of affordable hunting rifles, I don't think you can do much better than a Ruger American. Overall still very pleased.
If you're looking for a dual purpose target/tactical and hunting, the 783 may be a little better choice due to the thicker barrel. There is a real good price on one right now at buds: http://www.budsgunshop.com/catalog/product_info.php/products_id/84444
That puts it right in the range with the American's price. You'll just have to buy two Rem 700 front sight bases since the 783 doesn't come with any.