Choose a Weapon Type
A weapon’s type defines many of its key characteristics, such as the number of hands required to wield it, its bulk, and (for ranged weapons) its range increment. The type also sets the weapon’s starting damage die size, which other abilities might increase or decrease. Choose one of the weapon types— advanced melee, basic melee, heavy, longarm, small arm, or sniper—and note its base statistics found on the Weapon Base Statistics table, applying any die size changes.
Two-Handed Weapons: If you want an advanced or basic melee weapon that requires two hands to wield, increase the number of hands to 2, and increase the weapon’s damage die size by one step.
Sniper: A sniper weapon gains the sniper (250 feet) weapon ability. If it uses a battery, the weapon’s usage doubles. If it uses other ammunition, reduces its capacity by half.
Source
Starfinder Enhanced pg. 144