I got a weapon coil that has damage shock and freeze .... but you can't put it on any weapon that actually has shock and freeze like the sling or a war bow .... The only other weapon it will go on is a tripcaster which only has shock but no freeze, on all other weapons it will fit on have neither shock or freeze

What sense does THAT make? It's a completely wasted weapons mod

Yeah, I wouldn't use it then. Problem solved.

Not using what should be a good drop isn't a solution to anything ... I'm not farming Frostclaws on Very Hard for nothing, I should be well rewarded and this time all I got was a worthless Mod that should have been a good one but isn't because of a Bug that created an invalid combination that's not supposed to happen ......

Save the smart mark answers for the children

Unfortunately many weapon coils will drop with a stat combination that isn't fully usable in every weapon type. It's the primary effect/stat on a weapon coil that determines which weapons a coil can be applied too. In fact there's a very specific formula involved in determining which effects can be rolled on a single coil or weave, as well as the minimum/maximum values of each stat. If you want to know more about that then I'll simply point you to:
https://horizon.fandom.com/wiki/Modification
That page gives a very good breakdown of how modifications work etc and has details of all the unique modifications that can be obtained in Frozen Wilds including the optimal weapon for each unique weapon coil.

What you have to consider is whether the stats that can be used by a weapon are actually an upgrade to what you already have. If they are then make use of that coil until you get a better coil, if none of the stats are an upgrade then simply sell the coil. Modifications aren't really that difficult to farm, but getting really good ones that are ideal for your weapons can take a bit more time to find. Sometimes you may never get a full set of ideal coils for a single weapon, in which case you make do with the best ones you have available.

So according to that my mod (Hidebound Weapon Coil) only works on a rattler which I find to be mostly worthless and it seems most players agree according to that site

"The Rattler seems to be the least popular weapon among the players of Horizon Zero Dawn."

Thanks for a meaningful answer unlike that other reply which they should have just kept to them self

Ah yes, the Rattler is a rather limited use weapon, being short-range with a wide burst can make it fairly situational in use. I find it's quite good for dealing with groups of human enemies but beyond that it's usage falls off simply because there are other weapon choices that do a better job.

Hopefully you at least gained a better insight into modifications from the link I provided and can now put that knowledge to use within the game!

Weapon mod compatibility is determined by their primary stat, not their secondary stats. Yes, a weapon mod can have useless stats. Random loot is random.

The fire bonus double dips in power. It makes the fire bar fill faster,so it procs with fewer arrows. It also makes the burning effect more deadly.

Since it has 51% damage it's still useful even if the other two are doing nothing it's just not optimal except when used on a rattler. What was throwing me off is I couldn't find a weapon where all three perks were active but since I never use the rattler it was the only weapon I didn't try it on so it looked like a bug plus I read somewhere else (Reddit I think) that combination wasn't supposed to be available but that is obviously wrong

Go figure

Originally posted by russell_john:

Since it has 51% damage it's still useful even if the other two are doing nothing it's just not optimal except when used on a rattler. What was throwing me off is I couldn't find a weapon where all three perks were active but since I never use the rattler it was the only weapon I didn't try it on so it looked like a bug plus I read somewhere else (Reddit I think) that combination wasn't supposed to be available but that is obviously wrong

Go figure

That specific combination of stats in that specific order isn't normally available but that's what makes the unique modifications from Frozen Wilds truly unique. They have stat combinations in a specific order that you can't normally get on non-unique modifications.