T workers packin' heat

On the way out of South Station, Jesse notices two T guys refilling the token machines:

... Pretty typical overweight middle-aged vending technicians: sweaty underarms, world-weary expressions, just workin' another day, you know how it goes. But wait, what's this? Nothing much, just pistols slung on their cheap navy blue polyester workpants! Pretty big guns, too.

I wonder if there's a hierarchy of vending weaponry. Slingshot for Little Debbie's snack cakes, Bowie knife for Mountain Dew and .357 Magnum for those precious, precious subway tokens. Here's the question: what kind of weapon do you get if you're replacing the condoms and assorted 'novelty' items in men's restrooms and truck stops everywhere? ...