28 Vs. 20 Gauge: Which is the Better Sub-Gauge for Duck Hunting?

28 or 20 Gauge? WILDFOWL's Editor-in-Chief set out with Boss Shotshells and a pair of Benellis to find out which one is better for duck hunting.

May 09, 2025 By Skip Knowles

The racy little 20 gauge SBE 3 I was holding was a proven killing machine. I’d clobbered seven huge late-season honkers with it in seven shots last year over a few mornings with a tungsten-steel blend. By comparison, my wispy new 3-inch 28 gauge in the same model felt puny, and so did the shells. Could a 28 even come close to the firepower of the 20? They are two of the loveliest little semi-autos ever, but was there a big difference in the field? I have been shooting a 28 gauge for 10 years now, taking one with me to the flooded timber, and various fast-action teal potholes. I have enjoyed smashing ducks with tungsten/steel blends, a murderous combo, but how would it perform with the larger shot sizes needed for Bismuth?

I was about to get a stern reminder that it is patterns, not payload, that put pellets on a target, and that is what kills ducks. It would be a simple test. I wasn’t keenly interested in what percentage of pellets a certain load could retain on a typical 3-foot patterning target at 40 yards. This is a hunting magazine. I wanted to compare hits on duck-sized targets, so I chose 8-inch round stick-on targets by Champion. I would shoot each with the same 3” BOSS load of #4s with the same Benelli CRIO IM choke at 30 yards, then again at 40; typical duck ranges.

Two shotgun shells side by side on a fence line. — Boss Shotshells was the choice of shell to help decide which load packs a harder punch and groups better between a 20 and 28 gauge shotgun. (Photo courtesy of Skip Knowles.)

BOSS copper-plated bismuth is a big hit in the sub-gauge realm because it kills cleaner than steel without being overly costly like tungsten. So, I reached out to the boss at BOSS, Brandon Cerecke. Their credo is simple and honorable: “Conservation-focused elimination of cripples...executed through concise and direct (no BS) marketing.”

I was about to learn a lot. First, the 28-gauge 3” #4 is actually a 1 1/16-ounce load, heavier than I’d thought. The 20-gauge 3” #4 shotshell looks much larger, but it’s not much “bigger,” at 1 1/8-ounce. That amount (1/16-ounce) is negligible, Brandon told me. Velocity is the same (1,350 fps).

Then he surprised me. Neither of those loads was his personal preference in those gauges. Despite being the first to load 3” shells in 28-gauge, he will happily tell you the 7/8-ounce 28-gauge 2 ¾” load is where it’s at.

“The pattern efficiency falls a bit with the 28 when it goes to 3” shells,” he explained. “The 28 should be left alone. I don’t shoot the 3” shell. When I shoot 28-gauge it’s the 7/8-ounce 2 ¾”.”

“Setback” deformity happens upon firing when the pellets in the base of the shell are impacted by the pellets in front at rest. Buffers help with that problem. So, what about BOSS’s much-lauded walnut shell buffering?

“Even with our shells, the buffer only works so well…you still get to the point where you deform because of the pressure at the bottom with distortion,” he said. “I prefer the 2 ¾” 28-gauge. It’s the gun manufacturers pushing the 3”. I’m an efficiency nut over pellet counts. It’s the same with 20-gauge…true pattern efficiency is achieved with the shortest possible shot column height. Regardless of caliber, the taller the shot column, the less efficient it becomes. You may have more pellets, but efficiency drops off. 100 percent of 100 pellets is better than 60 percent of 150…and recoil jumps significantly with a heavier payload. Even with hard steel or hard shot, you still lose efficiency as pellets start bouncing off each other and disrupting patterns.”

The 28 is efficient in 2 ¾” because it was originally designed to be a “square load,” an archaic term from the days of black powder meaning equal volumes of both powder and shot, based on volume/diameter. Lengthening it undermines that efficiency. Shorter shot columns simply pattern better, he emphasized. “That 12-gauge 1-ounce load of ours patterned better than the 1 ¼-ounce loads, but people just can’t get their head around it.”

Hunters see the pellet counts (payload) in a shell as dollars, and they want their money’s worth. “But we have taken a lot of 3.5” guys and have them shooting 3” and 2 ¾”. You have to protect that shot column as best you can. And the recoil difference is big,” he said.

Does he reach for his 20 gauge when heading out on a typical duck hunt where most shots are 30-40 yards, with the occasional a little further? Or does he grab the 28?

“If I shoot anything sub it’s the 28 gauge. For ducks out to 40 yards, it’s Warchief #4s in 2 ¾” with improved modified choke, and call it done! It’s the 28 or 12 gauge for me, not the 20. Warchief 3 x 5s are good, but with the occasional shot past 40… I want #4s.”

I realized the 20 gauge was throwing most of the pattern high after the first shots, but even after a two-shot re-test aiming lower it still lost out to the initial two shots of the 28. The same standard issue Benelli IM CRIO flush chokes were used in both guns. This is as basic as a test can get (and there is always the shooter variable!), so what does it really show? Simply put, with the same gun model, load, and choke at the same ranges, my 28 gauge setup prefers that load more than my field-proven 20-gauge SBE 3. It also proves that the 28 is no weakling, and that the difference between the 28 and 20 with this load truly is absolutely negligible—it’s much more about the pattern and what the gun likes. And secondly, you better pattern your shotgun before season and find out what it shoots well, no matter what gauge it is.

Pattern trumps payload, that simple.

A downpour hit before I could test other chokes, but based on this experiment, and what Brandon said, I would not be surprised if a 20-gauge 2 ¾” load and a 7/8-ounce 2 ¾” 28-gauge load out-shot both of these 3” loads I fired in the test. It was also a good reminder to try to keep shots on ducks under 40 yards rather than shoot half a football field away.