"Large fusion power cell generates bolts of high energy plasma. High capacity and deadly accuracy make this weapon exceptional and easy to use."
The CM 451 Starburst is a fully automatic Energy assault rifle introduced in SAS: Zombie Assault 4. It can be a good substitute for the CM 351 Sunflare, since it has a bigger clip, pierce and damage, at cost of mobility and ammo cost.
It has a massive clip of 200, and used to be considered one of the weakest overall weapons with only 1400 DPS in the normal version, lower than even the Ronson 65-a (an early-found assault rifle), but it has recently been buffed to deal 250 damage in the normal version, thus making it a viable weapon now. The ammunition is a bit expensive at $1.2 for each round. However, its low ROF balances it out, making it drain less ammo and letting the massive clip last even longer. Later into the game, players will encounter the Mixmaster, which is very similar to this weapon, having a similarly large clip, fast reload, and energy damage. The Mixmaster outclasses the Starburst in DPS, at over double DPS with higher damage per shot.
In conclusion, although the Starburst can be good when it's initially dropped, its shortfalls generally put it behind other weapons.
The CM 401 Planet Stormer and CM 451 Starburst look similar, so much so that the Starburst might being an energy variant of the planet stormer.