Step 1: Brown the bacon until crisp in a cast iron skillet over a medium flame. Transfer to a cutting board to cool, then crumble or finely chop into a mixing bowl. If you like bacon fat, reserve it for brushing the buns.
Step 2: Add the pork to the mixing bowl with the bacon. Add the barbecue rub and stir with a wooden spoon to mix. Divide the pork into 4 equal portions and shape into patties. Place the burgers on a plate lined with plastic wrap. Lightly brush the cut sides of the buns with the melted butter and reserved bacon fat, if using.
Step 3: Set up your grill for direct grilling and preheat to high. Ideally you’ll grill over a wood fire or over charcoal or gas with a handful of soaked hardwood chips. Brush and oil the grill grate. Arrange the burgers on the grate. Grill until the bottoms are browned, about 5 minutes. Gently invert the burgers, using a spatula. However, never press the burgers with the spatula—you’ll force out the succulent juices. Continue grilling the burgers until cooked to taste, 6 to 8 minutes for medium. Use an instant-read meat thermometer inserted through the side of the burger to verify the internal temperature: medium should read 160 degrees.
Step 4: Transfer the burgers to a warm plate and let rest for 1 minute. (This relaxes the meat.)
Step 5: Meanwhile, toast the buns, cut sides down, on the grill, 1 to 2 minutes. Watch carefully as they can burn easily.
Step 6: Line the toasted buns with sliced pickles before topping with a burger. Add smoked slaw and serve at once.