What would it take for a double barrel customization to exist?

[roquepo]

Seeing that there was no way to add aditional barrels via customization when I learned about the existance of scopes and such was a big surprise. Recently I've been pondering about why this is.

The 2 big uses I see for this are taking the benefit of getting 2 consecutive special reloads (Hide + Sneak for example) and getting 2 shots without reloading when dual wielding.

Most mods that alter how a firearm works offer a trade. What would be needed for this to be more or less balanced?

At first I thought about less damage, but that would make most weapons into copies of the double barreled weapons we have now (most of them would be straight upgrades from the original even).

I thought about less range, increased proficiency required, no ability to up the damage when shooting both barrels, adding a missfire chance when shooting twice in a row or twice per turn... I think a combination of these could end with a balanced weapon in the end.

2 barrel weapons make things more interesting in my opinion and adding more of that to the game could be cool. If Paizo finds a way to insert a mod like this in a way that doesn't break the game I would be a really happy man, probably one planning to play a PC with a double barrel shotgun.

[aobst128]

The 2 options are basically simple weapons with less range. Hypothetically, add double barrel to any simple weapon, cut the range a bit and there you go. If you do the same thing with martial weapons, they would become advanced weapons.

[aobst128]

Only thing weird would be using both barrels at once, since you can't increase the fatal die above a d12.

[breithauptclan]

This might be better in homebrew subforum.

And could this be emulated by just changing/removing the interact action needed for changing barrels of a capacity firearm?

[VictorTheII]

While I was doing my extra crossbows homebrew there were a lot of odd decisions I had to wrap my head around in regards to Firearm design. Thankfully this was not one of those situations.

Double Barrel costs precisely a category increase and 10 less range. Its how you can turn a Flintlock Pistol into a Double Barrel Pistol, and a Flintlock Musket into a Double Barrel Musket.

[aobst128]

It is difficult to say how it might be balanced as an advanced weapon, since martial firearms don't only have a damage advantage. There's kickback and scatter to add to the power budget and 10 less range on something with more than 100 isn't a big deal. I'm more interested in kickback on 1 handed firearms. I wonder why they didn't do that. There's precedent with the sling because of propulsive. Would be great for a drifter.

[roquepo]

The thing is that the difference between simple and martial and martial and advanced in regards to weapon strength and ease of access is not the same. That solution might work for other simple weapons, but not necessarily for martial.

[Temperans]

Honestly, firearm rules are weird/bad enough that I see no reason why you couldn't add a double barrel modification. Just add some reasons as to why they aren't strictly better than single barrel.

[Puna'chong]

Maybe something like a more punishing Kickback that comes into play if you want to fire both at once, like 15 Str, but firing each barrel individually there's no penalty. On top of making it martial and lowering the range. Then reload each barrel individually.

Or it could be a modified Repeating weapon with Kickback that can fire both barrels in one action. Repeating I think has a built-in action economy of 3 actions to reload regardless. This seems kinda janky though.