i have 6 mccormick 10 rd mags i use in my single stack open 1911, never had a problem with 1000's and 1000's of rounds through them. they work equally well in my norinco limited/carry 1911. i also use wilson and ed brown 10 rd mags on occasion.
the mccormick mags were being used by nearly everyone i shot with that was still shooting a single stack in USPSA. this was long before the single stack class was introduced.
Awesome info, thanks.