Just from the remark "the shoulder thing that goes up," I would infer the sling (or, as I mentioned, a bra strap).
Don't ask how a barrel shroud equates to that --it's just part of the general fuzzy thinking of most emotionally and mentally crippled hyperleftists. It's a symptom of the "say something, do something, regardless of its sensibility" syndrome of that particular group of humans.
(I use the term "human" with great charity in my heart. Actually, they're more like the brainless drones of an ant colony.)
Terry, 230RN