Attacking incorporeal enemies with magic ranged weapons and mundane ammo

[Ravingdork]

If I have a +1 bow or similar projectile ranged weapon, and mundane ammunition, can I hurt incorporeal creatures? Or do I need magical ammunition for that?

I thought I knew the answer, but a recent FAQ that changed the way magical ranged weapons and ammo work has given me pause.

[Gisher]

The arrows would bypass DR/magic so I believe they would count as magical for purposes of Incorporeal creatures.

CRB wrote:

Ranged Weapons and Ammunition: The enhancement bonus from a ranged weapon does not stack with the enhancement bonus from ammunition. Only the higher of the two enhancement bonuses applies.

Ammunition fired from a projectile weapon with an enhancement bonus of +1 or higher is treated as a magic weapon for the purpose of overcoming damage reduction. Similarly, ammunition fired from a projectile weapon with an alignment gains the alignment of that projectile weapon.

[John Murdock]

the FAQ say just that the magic bonus do not help to bypass DR that a +3,+4 and +5 bypass, if the bow is magical the arrow is also magical, if the bow as an alignment the arrow also has that alignment but you need to buy adamantium arrow (which nobody will ever buy) to bypass DR/ada, coldiron/silver arrow to bypass DR/coldiron/silver, so since the arrow is also magical then you can deal damage to incorporeal creature for 50% less damage