M1903 Bolt w/D4 on Safety Lug

[thorin6]

I have a bolt, straight handle, milled extractor, small gas hole, with D4 on the underside of the safety lug.
Also, there may be a mark on the bottom of the bolt root but it's only a partial mark as best I can tell.
For what year(s) M1903 would this bolt be appropriate?
Thanks for any help.
If pictures are necessary I can post them later.

[John Beard]

Follow the link:

Bolt Steel Lot Code Chart

J.B.

[thorin6]

John,
Thanks
t6