PM ATLballaz or cs900, I believe you have to bore out the internal bore of the bolt, though I am not sure. Id advise against spending the cash on that though and just order an eigen bolt from lurker, or just wait for ATL's new bolt which is due for release really soon here.
yeah, Cs900 does great work and will have to bore the stock bolt out.
Highly suggest going another route and picking up an aftermarket bolt instead. Like Gutgut stated a Lurker or Atlas bolt will be pre-bored for you. Even Pooty's bolts are pre-bored and come with springs.