10 Gauge Vs 3-1/2″ 12 Gauge

Dear Technoid,

I am looking at purchasing a 10 or 12 gauge shotgun both chambered in the 3 1/2 and wondered which one ACTUALLY has the best bang for the buck. Is the 10 (3.5) more powerful than the 12 gauge (3.5) Can you shoot at longer ranges with the 10 instead of the 12, using the same shot size in a 3.5 inch shell? Please regard this as second priority and I am looking forward to your response.

Thank you,


Dear Kurt,

10 vs 12 is just a simple function of ballistics. All things being equal, a larger bore has more potential to heave more shot faster. Obviously, 3-1/2″ in the smaller 12 bore can’t hold the same amount of lead and powder as 3-1/2″ in the larger bore of the ten if all things are equal. [Technoidal rule #6 “All things are never equal”].

So, in theory, the 3-1/2″ ten is more potent than the 3-1/2″ 12 because it’s a .775″ bore 10 against a .729″~.742″ (backbore) 12. The ten has got to hold more stuff if everything is optimized.

But this isn’t a perfect world. Marketing forces drive physics, not the other way around. The 3-1/2″ 12 is the hot gun now, so it gets the attention and development work. The 10 was always a step child. Everyone thinks that if they buy a 3-1/2″ 12, that they can shoot everything from light 2-3/4″ target loads up to 3-1/2″ Roman candles. This means that with your 12 you shoot trap one day and launch a 3-1/2″ satellite the next, all with the same gun. It’s very appealing in concept. You can’t do that with a ten.

A quick tour of the reloading manuals and ammo makers’ catalogues shows rough parity between the 3-1/2″ 10 and the 3-1/2″ 12. There is a slight edge to the 10, but not much.

3-1/2″ 10 2-1/4 oz lead 1250 fps with Longshot powder
3-1/2″ 12 2-1/4 oz lead 1150 fps

3-1/2″ 10 1-1/2″ oz steel 1470 fps with Steel powder
3-1/2″ 12 1-1/2″ oz steel 1390 fps

Remington factory:
3-1/2″ 10 1-3/4 oz steel 1260 fps
3-1/2″ 12 1-9/16 oz steel 1300 fps

For all practical purposes, these numbers are pretty close. Obviously, the 12 will have a longer shot column and more shot deformation with lead shot, so it will require more tweaking for it to pattern as tightly at distance. Steel shot doesn’t really deform under setback, so the steel patterns shouldn’t be very different between the gauges.

So why wouldn’t any sane person always pick the 3-1/2″ 12 over the 3-1/2″ 10? Well, are you related to the Marquis de Sade? Do you understand the word pain? Do you have friends with shovels who can dig you out of the hole you shoot yourself into with a light 12 using 3-1/2s?

Ten gauge shotguns weigh 10 pounds plus. There’s a reason for that. Weight sucks up recoil. A ten isn’t meant to be carried any great distance, so it can weigh anything that comfort and “swingability” require. Most 12s are meant to double as upland guns in the manufacturers’ eyes. That means weights top out at 8 pounds, but are usually under. Another Technoidal equation “Big shell+Light gun=misery”. A gas action 3-1/2″ 12 like the Browning Gold helps a great deal. The recoil action of the Benelli SBE doesn’t help much at all. The pump action of the 3-1/2″ Remington 870 requires comprehensive medical insurance.

A lot of people claim that absorbing the recoil from a few thumpers doesn’t really bother them. I belive them. I’m sure that you could get away with a modest amount. Lots of guys with 3-1/2″ 12s carry a number of shells of different length. They use the lighter loads when their plaintive calls and quacks actually work and use the monsters on the bluebird days when a SAM missile is more appropriate. For turkey hunting, it makes sense to use all you can for that one head shot at 50 yards.

Personally, I prefer the 3″ 12. The main reason that I like it better than the 3-1/2″ 12 is that there is far more choice in 3″ guns than there is in 3-1/2″ guns. When you do go to a 3″ gun, you bring in all the soft shooting gas operated autos from Beretta, Remington and the rest. The difference in 3″ vs 3-1/2″ 12 payload is only 3/16 oz of steel (Reminton 1-3/8 oz 3″ vs 1-9/16 3-1/2″) or 1/4 oz of lead (Remington 2 oz 3″ vs 2-1/4 oz 3-1/2″).

Also, the best of the 3″ autos will happily shoot all sorts of light target loads. This means that you can actually practice shooting with your duck gun. I can’t emphasize enough how important this is. Being able to hit what you aim at with a slightly lighter load is far, far more important than missing the bird with a boxcar full of shot. “Magnumitis” is a social disease.

The 3-1/2″ pumps are also a compromise. Obviously they do nothing about recoil. The longer shell capability necessitates a longer “shuck” stroke. This may, or may not, be a problem for you. It is for me and I have long arms. Almost all the 3-1/2″ pumps are converted from the 3″ models by lengthening the receiver and bolt, while redoing some internal stuff. It isn’t always successful. The early 3-1/2″ Remington 870s had problems.

There’s yet another consideration with the long shells. There is a growing body of opinion that holds that a shell length should match the chamber length for optimum patterns. When a short shell is used in a long chamber, normal pattern variance is accentuated. There’s a bit on this in the Browning FAQ section on their internet site. If they are correct it means that you will get a better pattern from a 2-3/4″ shell used in a 2-3/4″ chamber than you will with that same shell used in a 3″ or 3-1/2″ chamber. I’m not taking sides on this one yet as it is still winter in Connecticut where I live so I won’t pattern. I try to limit my patterning days to the balmy ones.

Bottom line: 3-1/2″ 12 or 10? Up to you. I just want to point out that there is nothing miraculous about the 3-1/2″ 12. The 10 will be more comfortable to shoot and offer slightly superior ballistic performance. A 3″ 12 will be better for target shooting practice before hunting season, particularly if you prefer a gas auto. In between is in between.

Best regards,

Bruce Buck
The Technoid writing for Shotgun Report, LLC
(Often in error. Never in doubt.)

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2 Responses to 10 Gauge Vs 3-1/2″ 12 Gauge

  1. DaveBossardet says:

    Wow that was an awesome article! Thankyou


  2. Ken says:

    Well, I disagree. To settle this same argument a few years ago, I stacked my 12 ga. 3 1/2″ up against a friends 10 gauge. We shot at a 55 gal. plastic drum weighing around 50 lbs. My 12 gauge merely rocked the barrel back and forth. His 10 gauge knocked it into the cornfield next door. I’ll take the 10 ga. any day for power.


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