How do pinnacle drops work, getting what you want wise?

[frigid glacier]

So I'm 1580, with loads of pinnacles completed throughout a week and a large amount of gear which is 1580. However, i have barely any heavy weapon pinnacles,

causing a lot of the weapons i want to use to be under levelled. What is the chance of getting a pinnacle i want, or am i able to modify the chances to get what I want?

[visual orchid]

It's completely rng to what gear the pinnacle will be

[maiden mortar]

what are the chances, they are 1 in 8 chance they will be heavy

[hallow skiff]

The dares pinnacle is only a weapon

[frigid glacier]

alright thanks