That's actually the wording in the original Mage Hand Press book. I'm guessing it was an oversight. I hadn't noticed it until you pointed it out. 

Quote from R3ap3rG >>

I have a question regarding the Spellslinger subclass.

Finger Guns is a new, pretty interesting Bonus Action cantrip. I’m looking forward to using it.

Arcane Shot allows you to use your BA to add your risk die as damage. 

Unless I’m missing something, you can’t use both?

 Finger Guns is only a BA to cast, it lasts for 1 minute. So for the 1 minute after casting, you are using your Action to fire your attacks. 
So its only the initial turn that you can't use Risk die with it, but on the 9 subsequent turns you can very much do so.

Basically:
Turn 1: BA Finger Guns + ACT Attack with Finger Guns
Turn 2: ACT Attack with Finger Guns + BA Risk Die
Turn 3 - 9 Repeat or whatever else you are doing.

just a few small issues

#1)
The weapon mastery for the Revolver is incorrectly linked to the old revolver and not the new one added by this class. so, if u pick the new list of guns to get mastery with and choose the revolver (the starting weapon) you don't get that mastery u instead get mastery for the old 2014 revolver. 

#2)
Some of the starting granted maneuvers like "Maverick spirit" are hidden on the character creation screen so you have no clue it's even a feature until u finish character creation, even though there are situations like how the subclass "High Roller" features reference these maneuvers at later levels so it's really confusing that it's not displayed. they could be listed under "Risk" for simplicity

#3)
The maneuvers "Bite the Bullet" states "As a Bonus Action, you can expend one Risk Die to gain Temporary Hit Points equal to the number rolled on the die plus your Gunslinger level." but on your character sheet it reads as "As a Bonus Action, you can expend one Risk Die to gain Temporary HP equal to [4d8 + 3]." because the tool tips are displaying all your risk dice when is should only be tracking the bonus "Maverick spirit" has a similar issue.

#4)
 It seems like the new weapons with the firearms tag are still adding Dex to damage even though the new Firearm trait says;
"You don’t add your ability modifier to the weapon’s damage, unless otherwise stated. Firearm ammunition is destroyed upon use." and adding this damage is meant to be added at level 11. 

#5)
the Fighting styles that you can pick from were designed initially for melee weapons that the Gunslinger could apply to ranged weapons don’t appear to be linked to the new weapons added.

#6)
the feat "marksmen's luck" says "you can flip one of the damage dice over and use the number on the bottom." but it's unclear if we are replacing the original roll or adding to it. the feat Gun-Mage Adept just says it adds spells to your spell list but doesn't say if it gives u access to any spell slots or how to actually cast them. "Jam Weapon" should also make it clear they can't attack with that weapon not that they can't attack at all.

overall great class but some of the language on the new weapons/properties could be clearer & more upfront most people have always found things like the loading property to be confusing, and I think most people don't know that's different then reloading. some simple references would go a long way for a lot of tables.

Also, I don't know if it's possible, but it would also be amazing if we could adjust the weapons base damage dice values in some way for more customization.

Awesome, thanks for the tip on custom actions, I didn't realize how customizable it is. That will help solve a lot of different problems, however the issue of the stat modifiers is still a problem when using custom actions as, not selecting a stat for the action to use, will cause it to choose the default. So if I choose a ranged weapon action it will always use DEX unless I force it to use something else, but not using a stat is not an option if I want a weapon action it seems, and you can't add a negative modifier to counter Ballance it or use a general action as your chance to hit stat automatically adds to your damage, this might actually be part of what's causing the issues with weapons damage.
I just have one more thing to add about the weapon mastery options. When selecting if u want to use the new weapons or old ones it locks in both weapon slots, meaning if I create a Gunslinger, and want to have mastery in a Dagger and a Revolver, I can't select both of them. If I pick "Weapon Mastery (Player's Handbook)" until I can pick normal weapon mastery options. Also on that note, It seems the options for the new firearms are only available to gunslingers and other classes are not capable of wielding these guns properly without a feat, which I don't know if that was intentional.

The Gun-Mage Adept feat states that certain spells get added to your spell list, but the spells don't actually end up getting added. I put the feat on an Artificer to confirm, and it didn't add them to the list of spells the character could prepare. I'd love if this part of the feat could get fully implemented, because it would let DMs easily add spells to different classes' spell lists through custom feats.

Character sheet for reference: https://www.dndbeyond.com/characters/142865709

I had a similar issue when trying to apply it to the Spellslinger subclass.  You’d think these gun based spells would go hand-in-hand with casters who can use guns/canons

This is still happening for me.

Syncing has no effect. 

My players have been able to access the Gunslinger content, but not myself.

Is there an ETA on this getting fixed? I would like to use the content I excitedly paid for.

In the new gunslinger class guns with the firearm desciptor should not be adding abilitiy modifier, but on the character sheets they do.

The book says:

Firearm* You don’t add your ability modifier to the weapon’s damage, unless otherwise stated. Firearm ammunition is destroyed upon use.

It shows up both places you linked but not in the list of available classes on the Character Builder. 

It also says on the Marketplace that I own this digital product. 

Yes. And Mage Hand Press as a source. 

Website. 

I don't have any of those. 

Thank you for your input, everyone. 

Someone did something behind the scenes and now the class is finally showing up in the builder.

Peace be with y'all.

Just gonna state that firearms are still adding dex to damage rolls even when they shouldn't.

Character sheet for reference: https://www.dndbeyond.com/characters/148316887