I know there is a chart on the Sig site but it does not mention the 365 Legion. I also know from another post on this site that the barrels on the 365xl and the 365 Legion are different. But…will a 365xl complete upper fit on a 365 Legion lower? Thanks.

quote:

will a 365xl complete upper fit on a 365 Legion lower? Thanks.

Yes.

Yes, a 365XL slide assy works on the legion grip module.

The 365 Legion uses the 365 barrel and a ported 365XL slide.

It will definitely 'fit'. The only question would be whether the chin of the slide is long enough to extend back into the dust cover on the grip module. I believe it does, but I have no way (other than searching the internet) to verify this.