EE-23 modular weapon

The EE-23 sniper carbine was a long-range blaster and projectile rifle manufactured by BlasTech Industries. Modeled after the EE-3 carbine rifle, the EE-23 was able to utilize different types of ammunition, like energy cells for use as a blaster and ACP (Accelerated Charged Particle) clips for use as a slugthrower, and provided a longer range than its template.

When used in ACP mode, the shooter often switched from automatic to bolt-action mode for a better control over his weapon, although this was only utilized by most professional and traditional marksmen.

The weapon allowed various customizations, such as different types of scopes, silencers and even bayonets, grenade-launchers and bipods to be attached.

However, due to low demands, the production numbers were limited, although many military and paramilitary forces like the Mandalorian Protectors valued the rifle's accuracy, stability, long durability and its many ways of modification.

Behind the scenes
Although it's called "carbine", it isn't a short range weapon with low caliber. Think of the real-world Mauser Kar98k carbine and the Mosin-Nagant carbine, both professional long-ranged bolt-action marksman rifles in WWII.