Interesting. I didn't know that. I've never fired a 16-gauge that I can remember (maybe as a kid, but if so, that memory is lost in the mists of time), only 12s and 20s. 20s always seemed a little lightweight for my tastes. 12s are just right. So I thought 16s wouldn't pack the punch I like. Now I want to try one!
It’s a cult thing, much like the .41 Mag. Ammo is more difficult to find, so if you shoot them alot reloading is the way to go.
They usually pack 1 to 1 1/8th ounce of shot. The guns themselves are usually lighter than 12 gauges, sxs’s in the 6 to 6.5 pound range, making them nice to carry. They handle like a 20, and hit like a 12 on upland birds.
In repeaters, the Winchester Model 12 in 16 gauge is on the 20 gauge sized receiver. The Browning A-5 “Sweet 16”, is a light version of the heavier standard.
Other than high end guns, there production models available new. Browning occasionally makes a run of BPS, or a Citori. Remington occasionally makes some 1100’s or 870’s, both of which are on the 12 gauge frame, so why bother.