The 10 ga. had a brief resurgence when there just wasn't room for the early "light and fluffy" steel inside 3 in. 12 gauges for effective waterfowl loads. Early steel loads were extremely bulky for weight, and the paltry pellet count found in a steel "BBB" 3 inch 12 ga. load proved woefully ineffective compared to the lead loads that preceded it. There was simply not enough room inside a 12 ga. 3 inch hull for a stack of large, relatively light pellets.

The advant of the 3-1/2 in. 12 ga. appears to have finally killed off the 10 ga. for good. The 10 ga. has a SAAMI limit of 11,000 PSI to work with, the lowest of any reasonably common gauge. When the 20 ga. was punched out to 3 in., there was no allowed pressure increase. It was the same back when the 3 in. 12 ga. first appeared.

But, the 3-1/2 in 12 ga. is a different matter. Instead of 11,500 PSI to work with, the SAAMI spec was increased to 14,000 PSI. So, you have a lot more potential efficiency to work with in the 3-1/2 in 12 ga. than in the 10 ga. Now that no-tox shot has nearly equaled, equaled, or exceeded the weight of lead, depending on which manufacturer you believe, the need for tremendously more room inside a shotshell hull has vanished in concert.

That's it in a nutshell--the 10 ga. is dead, as you can actually get more performance out of a 12 ga. 3-1/2 in. load, with a less bulky firearm that is more versatile, lighter, better handling, less costly to shoot, with more factory load options. Federal Cartridge, for many years, has offered more factory shotshell loads than any other manufacturer, so I’ll use Federal as an example. Federal currently lists five 10 ga. loads in total.

Federal’s only lead "smaller pellet" load is the GST101 (originally named ‘Grand Slam Turkey’) that gets a 2 oz. payload of 4, 5, or 6 shot out the muzzle at 1300 fps. Federal’s High Density steel load is the new PHD106 load available in BB or #2 shot that moves 1-5/8 oz. out the muzzle at 1450 fps.

By comparison, Federal offers over SEVENTY-FIVE different 12 gauge shotshell loads, in a wide variety of shot sizes per load as opposed to the grand total of five 10 gauge loads. One 12 ga. 3-1/2 in. load, for example, is the PFC139, a 2 oz. buffered lead load. The Federal PFC135 actually offers a heavier payload in 12 ga. lead than found in 10 ga.: 2-1/4 ounces.

The Federal PHD195 12 ga. High Density waterfowl is the same as their 10 ga. load in both payload (1-5/8 oz.) and shares the same muzzle velocity of 1450 fps. So times have changed, and there is no particular reason for the 10 gauge to exist as a "preferred choice" anymore. The lack of shotshell choices, aftermarket choke tubes, the improvement in no-tox waterfowl approved loads, and the introduction of the 3-1/2 inch 12 ga. have all combined to moot its waterfowl advantage it held for a time, and its ponderousness for other applications makes it largely impractical.