Flame Rounds

Flame Rounds is a round trinket which causes the gun damage to ignite zombies. It reduces the damage you deal by 15% to compensate, but this does not affect the calculations, it only affects the gun damage dealt afterwards (the damage that does not ignite).
Flame Rounds helps to ignite based on the tier and damage. Further upgrading gives more fire duration from flame rounds.
It is not available in the worth menu.

Flame Rounds

Upgrade Levels	Cost (-)	Description	Dismantle (+)
Standard	25 Points/ 12 Scrap	Guns can ignite based on the tier and damage Up to 0.85x gun damage depending on tier rounds effectiveness Can only use one round trinket 100% fire duration from flame rounds	51 Scrap
Sturdy	13 Scrap	Guns can ignite based on the tier and damage Up to 0.85x gun damage depending on tier rounds effectiveness Can only use one round trinket 112.5% fire duration from flame rounds	11 Scrap
Honed	17 Scrap	Guns can ignite based on the tier and damage Up to 0.85x gun damage depending on tier rounds effectiveness Can only use one round trinket 130% fire duration from flame rounds	20 Scrap
Perfected	21 Scrap	Guns can ignite based on the tier and damage Up to 0.85x gun damage depending on tier rounds effectiveness Can only use one round trinket 150% fire duration from flame rounds	30 Scrap

Calculations

There are two calculations done for Flame Rounds - the chance to ignite and flame duration, related to fire damage dealt.

Chance to Ignite

The chance to ignite is 33% per 100 damage dealt and is entropically to ignite.
Example: If ignition fails, the chance of ignite increases.

Flame Duration

The flame duration is [(60% of Base Damage + 10 Damage)*(Flame Rounds Upgrade Level)]/(5 Damage/0.3 Second), rounded up to the nearest 0.3 seconds.

Example: 100 Base Damage with Perfected Flame Rounds that successfully ignites will cause a burn of 6.3 seconds of fire duration.