bolt lock early or late?

[sharmanajusmc]

In looking for a replacement for an old parts kit I found that sarco has two types of bolt lock. an early bolt lock and a late bolt lock... is this something to do with timing then? if so which should I get?

[mp44dude]

sharmanajusmc ,

Are you refering to the to the firing pin locking nut at the very rear of the bolt carrier?

If so either can be used; the later version is easier to use (take on and off)

greg