If you know that you will not be shooting any 3.5" shells, but the gun you want is available with 3" and 3.5", why not buy the 3.5 anyway since it will still fire your 3"? I assume that in a 3.5" gun the bolt will have a longer stroke, but does it make enough of a difference in cycling speed to make you opt for the 3" version instead?

Is it about the forcing cone or something else I'm missing? Thanks.

That's what I thought when I bought my SX3. I found one for the same price as a 3 inch model.

Several issues:

1) balance: often too much weight-forward

2) excessively long receiver

3) weaker receiver due to larger loading ports and ejection ports

4) more difficulty with light loads

5) extra, needless cost.

6) less pattern efficiency with 2-3/4 inch unfolded length shells that have excessive freebore in a 3-1/2 inch chamber.

I don't understand the cycling speed issue . I've never shot any semi that didn't cycle faster than my brain does when going for the 2nd or 3rd shot . Not once have I pulled the trigger before there was another round ready to go , never giving it a second thought .

A 3 1/2" scattergun is quite often uglier than a 3" gun...marginal but, there you have it.

What if I don't care about hunting? Why the hell would I want one?

Nothing else to add here. Randy nailed it.

If you are shooting clays and hunting with 3" shells and under; and rarely shooting at passing geese; do NOT get a 3 1/2" receiver semi-auto!

I think there are several good reasons for NOT buying a 3.5" gun if you're reasonably sure you'll never need or use the 3.5" shells.

The few 3.5" guns that I've shot have had rougher trigger pulls and just don't usually handle very well the lighter target loads that I like to shoot. There is only so much "adjustability" and "compensation" that can be made to a gun to make it handle both heavy and light loads.

Since there are lots of moving parts in a semi-auto, if it's designed to handle the heavy recoil of the long 3.5" loads, then it's not likely to be the best or smoothest operating gun for light 2 3/4" target loads.

I just think that a gun that is designed to handle the 2 3/4" (and perhaps 3") shells is going to be able to handle the light target loads that I want to shoot better than a gun that is designed to handle the much longer 3.5" shells along with the much heavier recoil of the 3.5" shells. I think this is especially applicable to things like trigger pull, sear springs, hammer/sear engagement, recoil springs, magazine springs, and lots of other things that must be designed to handle the 3.5" shells. If it's capable of handling the 3.5" shells and their recoil, then it certainly can't be optimized for the 2 3/4" shells without losing its capability of handling the 3.5" shells.

It's kind of like asking why not buy a heavy duty pickup truck when all you really need is a nice riding sedan. If it's built to handle heavy duty truck duties, then it's not going to ride and handle like a sedan that's built for comfort and fine handling. It may get you from Point A to Point B just like the sedan will, but the ride won't be as smooth, effortless, and enjoyable as in the sedan.

I specifically bought 3 1/2 inch guns because they are used primarily for waterfowl and I like the ability to shoot 3 1/2 inch shells. Which I will use this coming February on a snow goose hunt. I don't believe I am in any way handicapped with them vs my 3 inch chambered shotguns.

If its mainly for hunting there's not really much in the way of disadvantages going with the long chamber. Especially true for the likes of turkey and waterfowling hunting.

Lots of fabricated issues here. Lets take a look at them.
Balance is purely subjective. One may like the balance of a gun with a longer receiver. That's if there is even a difference at all or any that can be felt. Browning and Winchester models have no difference between them. How about the Benelli SBE II and M2 that are apart by .1 inch in overall length and .1 of a pound and use the same stocks and forearms. There are more that are the same or extremely similar than there are ones that are further apart. Take a 3" Remington 11-87. It balances with way more forward weight than say a Benelli SBE II, Beretta A 400 Xplor 3 1/2", Browning Maxus 3 1/2" or, A5 3 1/2".
I have shorter chamber guns that have longer receivers/ports than my longer chamber guns. Rotary bolt faces have done more to stretch receiver/ports than longer chambers. So what on both counts!
Name one 3 1/2" model other than the original 3 1/2" Gold that has receiver breakage problems? Pretty silly when you consider that 3 1/2" loads tend to be more powerful than shorter shells.
I've shot enough patterns on crate paper to stretch half way across Lake Michigan. I've not seen any tendencies that suggest a shorter shell does not pattern as well in a longer chamber as it does a shorter one. This is with dozens of different models with a vast amount of different shells that vary in brand, shot material, and load specs. Sometimes the 3 1/2" models patterns better than the shorter chamber guns with a particular 2 3/4" load. If it made much of a difference all target guns would be made with 2 3/4" chambers only. The one rule that applies to patterning is that every gun, choke, and load combination will yield it's own individual results.

3 1/2" models do tend to cost a little more that their 3" counterparts. What you get is more versatility in some cases and a chamber that's made to withstand more pressure.
3" models in general tend to cycle a little lighter load than their longer chamber brothers. Most of the better Gas operated 3 1/2" models do cycle lighter target loads all day long. These 3 1/2" models also cycle lighter loads better than some 3" or even 2 3/4" models. The light load cycling handicap has been shrinking year by year for the 3 1/2" models.

So, if it's mainly a target gun or for hunting like upland, go with a 3" model. For bigger birds go with the bigger chamber if you want.

Superb input from everyone. Thank you. I'm about to pick up a Browning Silver hunter which has both 3" and 3.5" options, and normally wanted the added option of being able to shoot 3.5" if the need ever arises, yet wanted to see if that would have a negative effect on performance when shooting shorter loads. Lots of food for thought here

Back when I used to hunt I shot loads of ducks and more than a few geese. The need for 3.5" ammo never arose. 3" steel and 3" tungsten matrix killed them all.

You should tell Beretta that their world-beating DT11 is made wrong with a chamber too long for target ammo......

I'm sure they'd love to hear from you.

The reason I didn't buy a 3 1/2 was because of the reports that 2 3/4 shells weren't as reliable and I shoot more clays than waterfowl so I want a reliable gun. I do understand every gun is different.

What are you hunting that you just have to have 2 3/4 inch ammo? I have shot wild turkey, geese, ducks on down to woodcock as well as rabbits and squirrels, etc., all with 3 inch ammo.

The 3-1/2 inch Remington SuperMag isn't as reliable as a 3 inch 870.

The Mossberg 935 is not as reliable as the Mossberg 930.

The Browning A5 3-1/2 in. is not as reliable as the Browning A5 3 inch.

A Kent Tungsten-Matrix ic 2-3/4 inch shell, 1-3/8 oz. of #3 @ 1375 fps is a better goose load than any 3-1/2 inch steel load and it isn't remotely close.

I have run many different loads from different shooters ,with my Beretta A400 Extreme Unico and never have had any cycling issues with the gun,it works well on the sporting clays course.

My Beretta Xtreme and Xplor Unico are chambered for 3.5" shells.
Both will cycle 7/8 oz loads all day long!
The Xplor is about 7 lbs and the Xtreme is about 7 3/4 lbs.
For goose hunting here I only shoot 3.5" shells.

I respectfully disagree with your assessment about 3 1/2” semi-automatic shotguns handling light loads. The Browning Maxus 3 ½” gun I bought last year will NOT cycle any clay target load lighter than 1 1/8 ounce at 1200 fps or greater. I’ve tried at least a dozen different lighter factory/reload fodder and ALL of them fall short. I traded a Beretta Extrema 3 ½” in on the Browning that suffered the same inability to cycle lighter loads.
If there is any chance that you will be using the gun for clay target games, I would recommend the 3” version over the 3 ½” version of ANY brand semi-automatic shotgun. It’s never a problem with pumps, O/U or SXS, but 3 ½” semi-autos are prone to function problems with lighter loads.

My SX3 is basically the same gun. I use it as a waterfowl gun and I have experienced none of the issues brought up here. If it was an all around gun for clays and upland, I might think about it. I wouldn't buy a new gun just to get 3.5 but if that option is available I would take it again.