I shoot skeet now and again and have seen many guns on the range. Semi autos, pumps, (the Remington 870 is by far the most common), and over/unders (which I use). I have never seen a side by side there. I know that with a O/U the lower barrel in the first to shoot, as it has the most open choke, and has the least “Lift” in the recoil. Mine is a 20 ga choked cyl and mod cyl. Is there any such convention with a side by side? is the right or left barrel the tightest? And is there a good reason I never see one on the skeet range?
Left barrel is the tightest choked one, triggered by the front trigger in dual trigger double-barrels. Right barrel is the tighter-choked one, triggered by the rear trigger.
As far as skeet, I have no clue as to why you do not see them there.
As to single-trigger double-barrels, I have never owned one and do not know, just think that the first pull will trigger the left barrel, and the second pull will trigger the right barrel…unless the first trigger pull fails to fire…this is why African big game double-barrel raifles had two triggers. Not an issue with dove shooting in North America. 
Thanks for the info. BTW, my O/U is single trigger, and has a selector button. Move the button forward, safe. back, fire. Left, lower barrel first, right, top barrel first. I don’t trust the safety much anyway, I leave the action “broken” or open, I am not sure of the correct term, until I am ready to shoot while hunting. It is a certain way to make sure the gun cannot fire if you trip or stumble. Snapping the action into battery is a natural move while bringing the gun to bear anyway. That is one reason I went with a O/U and not a more modern repeater, I think it is safer. On the skeet range it is not even loaded until I am ready to shoot, and even I can keep focused on what I am doing for the three seconds between loading and yelling PULL!
SxS Shotguns also have a different convergence range to a UxO shotgun- a UxO shoots on a straight line, whilst if you have a look at an SxS, the barrels are slightly closer together at the bore than at the breech.
As a result, an SxS has a different sighting plane than a UxO. SxS shotguns are also generally considered “hunting” guns, whilst UxOs are seen as “Sport” guns.
More importantly, you’re not likely to pick up a 2nd hand UxO for under $500, whilst a 2nd hand SxS is about $250-$300.
The big advantage of SxS shotguns, IMO, is that you can fire both barrels at the same time by simply pulling both triggers… 
One can’t be too safe when dealing with firearms, so kudo to you.
Perhaps someone will come n here to explain to both of us why the side-by-side is not the preferred shotgun when shooting skeet…I am very curious, too…there must be a reason why the over/under is the preferred piece.
My understanding was that the side-by-side was only widely used in the sport of hunting men romantically interested/entangled in your daughter?
Why, is your daughter attractive and over 18?
(I’m joking! My fiancee would not take kindly to me running off with an 18yo… :eek: )
Seriously though, SxS shotguns also have a different “Comb” of the stock, and they handle differently, too. They’re good for hunting because you can carry them broken open in the crook of your arm (it’s not especially comfortable with a UxO), but they don’t acquire a target as quickly as a UxO- and they sight on a slightly different plane, as I mentioned earlier.
It’s a bit like asking why more people don’t try and compete in the Paris-Dakar Rally with a Toyota Hilux- sure, it’s a 4WD, but unless you modify it a bit, it’s not really the best thing for the job.
not arguing with your facts, (Who would argue gun facts with a name like Martini Enfield?). But would not the convergence thing make the gun “cross-eyed”? I mean at the point of convergence it would be awesome, but beyond that point the right barrel would shoot to the left, the left barrel would shoot to right. Being a short range firearm to begin with, does it really make a difference? I am just wondering why a gunsmith would go to all the trouble to skew the barrels. I am thinking of a freind of my dad, who flew fighter back in WW II. I think he flew a P-47. He said they could adjust the guns (on the ground not in flight) so they all fired forward, or converge at a point. He had his set to converge but admitted if you did not get the target at the right range, you were pretty much just spraying. I really don’t remember, but I am thinking the convergence point was like three hundred yards.
Perhaps you have nailed it Martini, the O/U is not the most comfortable to carry broken in the field, but it is easy to get used to. The sighting plane is a big issue. I never carried a SxS in the field, but in the gun shop the O/U came up and felt better, faster on the draw so to speak. I bought mine in the early eighties, and it was a whopping 375 bucks. Two weeks pay assuming I did not eat or pay rent those two weeks. And by a no-name manufacturer, Richland Arms. A Browning was about a 1000 clams then. I could have chosen a SxS for about 200 dollars. Two barrels, a stock and a trigger mechanism. Why are O/U so much more expensive? By the way my cheapie Richland Arms O/U has served me well, so no slam on them.
In theory you’d be right- eventually the right barrel would shoot left, and vice versa, but the realistic range on a shotgun is so short it’s not really noticeable.
The convergence range on Spitfires and Hurricanes was, I believe, 400yds (or something very similar).
I’m not a gunsmith, but if you look at an SxS shotgun closely, you can see the chambers are a couple of millimetres further apart at the breech than the two bores are at the muzzle- I’m pretty sure it has something to do with the chamber pressures generated by firing the shells.
The locking mechanism on UxO shotguns is, from what I understand, “stronger” than that of an SxS, and there’s a larger rib between the barrels.
I have to confess shotguns aren’t my area of expertise (as the name suggests, British & Commonwealth Military Firearms are!), but I’ve handled enough of them to know that a UxO is better for Clay Pigeon Shooting, albeit in a variety of nuanced ways that really don’t make much sense to non-shooters, or even fans of certain types of shotgun. (FWIW, I’m an SxS man, but I’d probably have a Mossberg if it were legal to own pump-action shotguns for sporting use here…)
Thanks for the info Martini. Just chosing the right tool for the job I guess. I have a Remington 870 Wingmaster that my dad gave me on my 16th birthday, (16 gauge no less). It is a fine gun for pheasant in the corn fields of Illinois, but try swinging that 28" longer than all git out barrel in a Wisconsin woods where grouse is the game and you will find a tree right in your arc. Besides, 16 ga shells are damn hard to come by any more. The O/U has 20" barrels and is much better in the woods. Skeet was a thing an alleged friend ( I say alledged like the drug dealer is your friend) introduced me to. I am a little long in the tooth, not able to get around like I used to, and now “Hey! I can shoot without all the walking?!” It is a little addictive. I bought the gun for grouse, but it is an excellent skeet gun. Not bad for home defence either, with 3" number six duck loads. Deadly, but will not blow through two houses and kill a bystander a block away. My first line of home defense remains my trusty “Sam Snead” 2 iron golf club. Used it once. Guy (drunk) tried to come inside. He thought he was home. Told him to go away. He insisted, I brandished my two iron and said I was going to put his head on the green, he stayed at bay and my wife had time to call the police and they gave him a safe place to sleep it off. Have a nice day.
I’d be interested to know if you ever tried this with a 12 ga.? If so, how’s your shoulder?
I’ve done it more times than I can count, and my shoulder is fine.
To be honest, I fired my 12ga SxS with both barrels quite often and found it to be unconscionably good fun, but not very practical.
Sadly, I had to sell it late last year (some unexpected bills came and I thought “I can always buy another shotgun, but the Power Company cuts you off pretty damn quick if you don’t pay your power bill”).
Of course, no sporting shooter’s gun cabinet is complete without a shotgun in it, so I picked up a Greener GP shotgun (think a Martini-Henry in 12ga), which has proven surprisingly adept at stopping impis of charging hares, pheasants, and ducks…
I have shot both skeet and trap (althought it has been quite a while). I was always told that OxU’s sight more naturally. Never shot one myself, I was always using single barrel semi-autos and pumps. I could see where an over under would be a more natural transition for people used to using single barrels since the sight picture will be almost if not identical.
Just correcting my own self. I just noticed my goof. I meant to type “Left barrel is the less-choked one…”
Sorry.
This is mostly anecdotal, as I shoot skeet and sporting clays for fun, and compete in trap. Skeet has four discplines, .12, .20, .28 and .410. The guys who compete in this sport may have an O/U with four sets of barrels, or more than one shotgun for each gauge, or they may have a multi-gauge tube set. I have yet to see a “modern” S/S with this type of configuration. I use modern in a sense that the gun is a target grade model built in the last 20 years.
Another reason is that older S/S shotguns usually have fixed chokes, as described by the OP. This restricts the use of the gun depending on the type of targets it can be used on. The OP’s IC/M chokes are an excellent setup for skeet, hunting quail or dove, but is impractical for larger birds at longer yardages. Almost all modern guns now come with removable choke tubes and there are a number of aftermarket choke tubes designed specifically for each sporting application, ie. trap, skeet, sporting clays, pigeon shoots.
With fixed chokes, the purpose of the two-trigger setup was to allow the shooter to fire the appropriate barrel first, with the advent of the selective trigger, most (modern) guns in the US are single trigger with a selector switch. Traditional two-trigger guns are prevalent mostly in Europe.
The Beretta BL-4 that I use (actually have 2 of them) has a selector that allows you to fire the upper or lower barrel first. So if you are shooting something moving away, you can fire the wider choke then the tighter choke. If you are shooting something coming at you (like a dove), you can shoot the tighter first. It’s also handy if you only want to load one shell, you can load either barrel and select it to fire.