Sig FCUs (P320, P365) - How are they classified on the 4473 form?

[GC7]

Pistol? Receiver?

 

[harley128]

My guess would be "other"

 

[1911master]

I would guess other much like a stripped AR lower.

 

[OKNewshawk]

Since they're considered the firearm, they would be classified as "pistol." They're no different than a complete P320 or P356, they're just missing the plastic "wrappings."