Since it's going in a Turbo action, I'd copy the Turbo bolt. But, I'd bet by the time you buy whatever tooling you have to get to make the bolt and material to make the bolt, plus whatever heat treating you use, you'd be money ahead getting the bolt from Flash. It's just like Butch's Aussie wind flags, by the time you figure up all the bearings, delrin, reamers, etc and any kind of allowance for your time, you're better off buying the flags from Butch. By the way, Butch, I need two more wind flags. Send me an invoice and I'll get you a check.