Paul,
I agree that it does seem strange to show the same restrictions for 10 GA as 12 GA, but I had only two charts that listed the 10 and both show the same as 12 GA, with three exceptions of I.C., Skeet II, and M. One of the charts is on this website.
http://parkerguns.org/pages/faq/ChokeSize.htm
I'm happy with the 10 to 12 Gold Gauge Mates for they do stay in place if one uses enough grease on them. If you shoot higher pressure loads in good reloadable cases (WWAA and RP STS), it blows out the sides of them. But I'm shooting a 24 gram load with 3200 psi and it leaves a crease but does not make them useless.
Threaded Mode