Quote Originally Posted by Aragorn243 View Post
Theoretically, the parts are interchangeable throughout the entire series so long as it has that mum stamped on it.
Possibly with the Type 99. Type 38 bolts seem to come in two basic variants as regards geometry of the locking lug faces: 90° to the bore and inclined plane. (like the M1917, etc.)

Have yet to note that drama with Type 99s. Whether the headspace issue is worth pursuing is up to the user. Have yet to have a problem with Type 99s, matching bolt or not, but... (Type 38 bolts have been found to vary a good bit, though- almost as much as US '03 bolts!)