Guild Wars 2

I was just wondering how did I manage get a killing blow with Rifle and Sword
when I’ve not/can’t equip my Ele with those weapons? (I only have one char)

Maybe you picked up some environmental weapons somewhere? (Only thing that comes to mind is the dredge sonic rifle in Bloodtide Coast)

Maybe the conjured greatsword counts as a sword?

Other than that… not sure.

Certain forms, or items can give those to you.

For instance during the priory story you are forced into gaining about 90 kills with a greatsword, regardless of class.

I assume you may have killed something while in a different form, or while holding a specific bundle item that counted as a sword or rifle.