If this is something you’re asking, you’re about to save money and open up your ammo selection.
A shotgun with a 3-inch chamber will work flawlessly with both 3-inch and 2 ¾-inch shotshells. You can shoot a shorter shell, but cannot shoot a shell longer than your chamber is marked for.
Why don’t 2 ¾ inch shells jam in a 3-inch chamber?
Because a 2 ¾ shell is shorter, it’s definitely going to fit into the chamber of a shotgun. Since all 12 gauge shot shells are the same outer diameter, it will slide in and seat perfectly in the chamber. It’s shorter, but it’s not so short that it will fail to feed from the magazine.
2 ¾ inch shells are still long enough that they will stay in the right orientation in the magwell and feed properly. If you try the 1 ¾ inch mini shotshells, they will actually turn halfway around and get stuck. Not the 2 ¾.
If you have a break action, pump action, or bolt action shotgun with a 3-inch chamber, the 2 ¾ will cycle and fire exactly as the 3 inch will. If you have a semi auto, you may need to adjust the recoil. Some semi autos have a different setting to cycle the shorter, lighter loads.
Since the metal rim is the same size, the bolt face will still grab and hold the shot shell properly as it is fed into the chamber. The ejection system will work without a hitch too. The shell will be pulled out of the chamber and go flying just like normal.
Is it safe to fire 2 ¾ inch shells in a 3 inch chamber?
There are no special safety concerns when shooting a 2 ¾ shot shell in a 3-inch shotgun chamber. Since the shot shell is inserted into the chamber right up to the rim, or seated on the rim, the entire shell is supported by the bolt face and chamber. The shell could be only ¼ inch and if you put it in the chamber and close it, it will fire safely.
The pressure is lower in a 2 ¾ inch shell than in a 3-inch There is nothing about the 2 ¾ inch design that could cause an over-pressure issue in a larger chamber. It is well within safe operating standards. You don’t have to worry about the firing as the bolt is being closed (slam firing). Firing out of battery isn’t going to happen with it either.
How many 2 ¾ inch shells will my 3 inch shotgun hold?
So, you can safely and flawlessly fire 2 ¾ inch shells in a shotgun with a 3-inch chamber. That’s great news. Besides now having a larger selection of ammunition you can fit more shot shells in a tubular magazine, right? Well, not exactly.
Most shotguns have a tubular magazine instead of a box magazine like most rifles do. The capacity in a tube is only restricted by the length of the shell. If you put in a shorter shell in, you have a bit more capacity, in theory.
Most shotguns with a 3-inch chamber hold 6 shells in the magazine. Unfortunately, that same magazine will also hold only 6 of the shorter shells. In fact, in order to hold one extra shell, a 3-inch chambered shotgun will need a standard capacity of ten, 3-inch shells.
Now if you just did the math in your head, that probably doesn’t make sense. Ten 3-inch shot shells requires a 30 inches magazine. 30 inches will not quite fit 11 2 ¾ inch shells. It would only fit 10.909 of them. But there is always a bit of extra space in a tubular magazine so you aught to be able to fit eleven 2 ¾ inch shells in a ten, 3-inch capacity magazine.
What is Difference in Power Between 3 Inch and 2 ¾ Inch Shells?
A 3-inch shell definitely has more potential for power than a 2 ¾ does. The extra quarter inch can be filled with gunpowder, shot, of some of both. You can have more weight, more velocity, or a little more weight and a little more velocity in a 3-inch shell versus the 2 ¾.
Most 2 ¾ inch shells have an eighth ounce less shot (1 ounce) than the 3inch shells (1 1/8th ounces) . Because they have less shot, they can use less powder and get the same velocity. A one-ounce load of shot will have about 12 percent less full of a pattern (shot density) than a one and an eighth ounce load.
A 3-inch shell can easily get 200 feet per second more velocity than a 2 ¾ inch shell with the same amount of shot. 200 feet per second may not sound like much, but that can be 20 percent more overall energy.
3-inch shells are generally a significantly mote powerful option in a shotgun.
That being said, the shorter shells aren’t exactly low power. The 2 ¾ shell has been killing animals from ducks to deer for a century. It’s generally more common than the 3-inch shells, and a bit cheaper. There is also usually a bigger selection on store shelves in the 2 ¾.
So now you know. If you see a shell you like in 2 ¾ and your shotgun says 3 inches, don’t worry about using it. shooters have been doing this for half a century, and gun manufacturers have taken it into account with their designs.