Okay, I figured it out. Solarius needs to fix his moon regions.
You're getting the UAC moon base instead of the MiB moon base, and are thus stuck instead of progressing.
![Sad :(](https://openxcom.org/forum/Smileys/default/sad.gif)
Try these with the your save and see if the moon people change their allegiance.
So is being at Promo III to early to get the damage reported? Of all the weapons I've researched, this was the first one to pop up without reporting the ammo/damage capability. That kind of stood out after so many weapons were researched.
IDK, the mod is so random it's hard to predict an individual playthrough. You usually have some sort of 7.62x51 weapon by Promo III, but apparently not always.
I take it you never tried to secure a source of 7.62x51?
I imagine one could have Ufopedia display without the ability to buy the stuff, but that'd mean Solarius has to create a third research for all of these weapons. Doubt he's enthusiastic about that.