[Pathfinder] Running Carrion Crown, need some advice!

[kornwiser]

Hey, I am running the Carrion Crown adventure path for my group, we just finished our first session yesterday. I've got two issues:

1. I am running the adventure for 5, instead of 4 as it was designed, and...

2. We rolled for stats, and everybody rolled...very well. Everyone is above the curve for normal point-buy.

What are some ways I could appropriately bump up the difficulty of the challenges so they don't curbstomp their way through Harrowstone?

Here's the party makeup:

Human Paladin of Cayden Cailean
Half-Elf Magus (Bladebound)
Ifrit Samurai (Sword Saint)
Human Gunslinger
Half-Orc Oracle of Battle

Any help would be much appreciated!

[Deathkeeper]

For the start, try just increasing the HP of baddies by a bit or adding another zombie or two to encounters. Trust me, they'll handle it.
Played straight though remember that CC is often a higher difficulty campaign. If you want to make it as hard for 5 strong PCs, you can add some class levels to bosses or just make them play smarter. If you don't care about making it super hard, don't add too much and see how the players do. Consider not adding very much to the loot tables- making them strapped for loot can also make tactics more important for survival than raw power, but don't be so stingy that it gets annoying.
PS- looks like they don't have a Rogue. They'll have fun going through Harrowstone looking for keys to every safe/smashing them open ruining potions. Unless the Oracle took the Curse that makes locks explode around him.

[Corlindale]

We ran through it with 5 and were still quite challenged most of the time, it's a fairly high-difficulty campaign. We had reduced XP progression because we were 5, and loot wasn't all that plentiful either.

I'd recommend just starting out to see how bad the problem is, using less XP as is standard for 5 players.

[kornwiser]

Well, they've only gotten in one fight so far - the giant centipedes in the false crypt, which they demolished. I'll see how things go once they actually get to the prison, but I'll try bumping up the HP and maybe adding a monster or two to each encounter. If I have any more problems I'll let you guys know - thank you!

[Squirrel_Dude]

The only advice I can give is about gunslingers and how they effect CR. Because gunslingers often only attack touch AC, if you have an enemy who's primary form of armor defense is based on natural armor, they're going to destroy them.