Sig P320 can use 4 calibers, different size barrels of different size frame. I use the trigger module from Carry size and 9mm carry size barrel in compact grip.
Shoots like a Sig, doesn’t have feed, ejection or any ammo sensitivity. Good Striker trigger with short reset you can hear and feel.
A Dandy.
Sig P320 system
I pass by the Sig Academy in Exeter NH every day on the way to work.
They have a HUGE showroom in there open to the public.
A GIANT candy store for us adults.