Combination weapons and reloading strike from Drifter

[XAHTEP]

So I have a problem with reloading strike not working with combination weapon

Reloading Strike Requirements - You're wielding a firearm or crossbow in one hand, and your other hand either wields a one-handed melee weapon or is empty.
You make a melee attack and then reload your gun in one fluid movement. Strike an opponent within reach with your one-handed melee weapon (or, if your other hand is empty, with an unarmed attack), and then Interact to reload. You don't need a free hand to reload in this way.

Rapier Pistol
Uncommon Combination
Price 10 gp; Bulk 1 Hands 1
Martial
This elegant weapon is shaped similarly to a rapier with a pistol down the length of the blade

Melee
Critical Fusion, Deadly d8, Disarm, Finesse
Damage 1d4 P
Group Sword

Ranged
Backstabber Concussive Fatal d8
Damage 1d4 P
Range 30 ft.; Reload 1
Group Firearm
Ammunition Firearm Ammunition (10 rounds)

So the thing is, when it's in sword form, my dm says it's no longer a firearm so you can't reload it with the strike. But you can reload it in sword form with a normal action. So i don't get it.

[Red Griffyn]

Put a bow gauntlet on your other hand so you qualify as having a 1H crossbow while it is in melee mode. The wording has been tweaked slightly to remove any question of whether it has to be the qualifying ranged item that gets reloaded:

https://app.demiplane.com/nexus/pathfinder2e/classes/gunslinger-rm

Sounds like your GM is being very pedantic.

[YuriP]

XAHTEP wrote:

So I have a problem with reloading strike not working with combination weapon

Reloading Strike Requirements - You're wielding a firearm or crossbow in one hand, and your other hand either wields a one-handed melee weapon or is empty.
You make a melee attack and then reload your gun in one fluid movement. Strike an opponent within reach with your one-handed melee weapon (or, if your other hand is empty, with an unarmed attack), and then Interact to reload. You don't need a free hand to reload in this way.

Rapier Pistol
Uncommon Combination
Price 10 gp; Bulk 1 Hands 1
Martial
This elegant weapon is shaped similarly to a rapier with a pistol down the length of the blade

Melee
Critical Fusion, Deadly d8, Disarm, Finesse
Damage 1d4 P
Group Sword

Ranged
Backstabber Concussive Fatal d8
Damage 1d4 P
Range 30 ft.; Reload 1
Group Firearm
Ammunition Firearm Ammunition (10 rounds)

So the thing is, when it's in sword form, my dm says it's no longer a firearm so you can't reload it with the strike. But you can reload it in sword form with a normal action. So i don't get it.

No your GM is misunderstanding.

Combinations weapons are not modular weapons. They are at same time ranged and melee weapon and belong to both groups at the same time. The action that you uses to change its usage it's like change a grip this won't change the weapon group it still a firearm and a sword and you can reload it normally. Nothing in Combined traits or rules states that weapon changes its groups when you change its usage, weapons keeps their groups even when sheathed.

You are using a rapier that have made with firearms part. You change your grip to use it as a sword or to put your fingers in the trigger and starts to aim and uses it as a firearm. It's not a Ruby Rose's scythe that transforms itself into a scythe or rifle.