Head Stamps from Lot Numbers XM777/7.62 NATO Reference

Ok, I have a box of XM777 and 7.62 NATO reference ammo that’s still sealed (I added the plastic). Is there a way to tell the headstamp from lot numbers? Are there documents available to research such issues?

The XM777 was only made for a limited time period as a possible candidate in the NATO trials for a future 5.56 mm NATO cartridge. It had the shape of a M193, but a steeel penetrator in the tip like the later M855.
The earliest mention I know of is in the American Rifleman of April, 1977. See also your HWS Vol. III, pages 71 and 91. Therefore the year would be between 76 and 78.

Roger that, I knew the years and that it was a pre-855 load, just too bad we can’t tell the exact stamp without opening the box. Thanks JP

Here the drawing of the XM777 penetrator:


1 Like

Thank you for sharing.

JPeelen, do you know the weight of bullet in the 5,56 XM777 ?
Thanks in advance.

It is a 54gn bullet.