That definitely looks better for throwing, you did a good even grind Chris. By the way O1 is too soft in the annealed condition for throwing. That ring will get dented and bent. The book calls for a 800 to 1000 degree temper, 50 to 44 RC. Chris that means you'll have to use your HT oven for the temper.
Here are some concise and clear instructions for O1.
http://cintool.com/catalog/Oil_Hardening/O1.pdf
O1 is never used for shock uses like throwing knives. Like Carl said he would use 5160 or rebar which runs at lower carbon content. O1 is just too expensive for throwing knives, but I understand you didn't intend to make a throwing knife initially.
Problem with 5160 is most suppliers sell it 1/4" thick, which is fine if you want to forge it. New Jersey Steel Baron list 1045 for sale, but is out of stock. Now also you can check with a local machine shop and see if they will sell you some 1045-55 flat bar or 4140 if you want to make throwers of high quality steels. Problem with some of the online metal companies is they charge way too much for shipping and they carry these steels as do many machine shops.