This is one of the things that makes Bucky a great hero. Giving you 4 attack is good, but piercing and ranged is excellent, and better than they might even normally be since one of the things about bucky is you want to be searching up minions pretty often with Spoiling for a Fight and Looking for Trouble but the problem is a lot of minions have troublesome keywords like toughness or retaliation.
The winter rifle basically trivializes a massive chunk of minions, since anything with 4 or less hp is D.O.A regardless of what keywords they have; which is a large chunk of minions out there. Add on Bambino and you can one shot most enemies in the game, including his nemesis Crossbones if you want to Face the Past (which can be a good shout since divorcing Crossbones from his scheme Hydra Hit Squad makes them both much easier to handle).
Can definitely recommend running it alongside Lock and Load & Bambino since his power makes it trivial to clear the side scheme and pull out some amazing weapons.