101Leafy researched the games.
Lunastra's Cannon

Incorporates Lunastra materials into this Bowgun's simple yet powerful design.
A blue giant cannon modeled on Lunastra, the counterpart to the Teostra heavy bowgun. It can use few special rounds, but its firing mechanism, which pushes the round out with the whole barrel, is very powerful, and in the right hands it can take down many monsters with nothing but Normal shots.
Our translation of 復刻 ハンター大全 (KADOKAWA / Enterbrain, 2014), page 172.
| Class | Heavy Bowgun |
|---|---|
| Rarity | 5 |
| Attack | 264 |
| Defense | +15 |
| Slots | 0 |
| Reload | Average |
| Recoil | Medium |
| Table price | 5,250z |
Listed in the equipment tables of モンスターハンターポータブル 2nd G 公式ガイドブック (Enterbrain, 2008), page 784.
Ammo
From モンスターハンターポータブル 2nd G 公式ガイドブック (Enterbrain, 2008), page 784.
Materials
Lunastra Shell ×4, Fire Dragon Scl ×6, Lunastra Mane ×2, Firestone ×1