The nearest I can tell, I will give up 4 to 6 birds, on a round of 100, by shooting the S x S, compared to my MX-8s.
SRH
Why is that, Stan? On as purely an objective, apples to apples, basis as you can describe....barrel length, chokes, stock dimensions, weight, balance, MOI....how does your SxS compare to your MX8? If you have to make a single apology for the SxS in any one of those respects, then it's a condemnation of the particular gun, not SxS's as a species. Right?
I competed pretty well at sporting and FITASC with O/U's for a dozen years or so. When I ran out of mods to keep my interest fresh I switched to SxS's exclusively. Having stocked a half dozen target guns to suit myself I set out to apply what I'd learned about gun fit and target shooting to a SxS comp gun. I wound up with a a 32" barreled Fox, choked .022/.022, weighing 8.25 lb and balanced as I like. My only regret is that it didn't come in at 8.6 lbs. The only way that would have been possible would have required 3-4 ounce heavier barrels from the get go, and that wasn't in the cards. That resulted in a short learning curve to get accustomed to the slightly lighter weight. But o more so than my earlier experiences with growing barrel length and weight in my O/U's.
I've now put over 50,000 rounds through the big Fox in virtually every clay target venue. All it gives up on the skeet field is what any other gun with .022 choke would give up. All it gives up at 16 yd trap is the extra 1.25 lbs I prefer. Of the meager 40 or so rounds of bunker trap I've shot, my highest score was a 23...one shot kills from a low gun start with this SxS. If I still shot registered sporting, I'd never hesitate to play the HOA option with this gun.
I'm sure it sounds like I'm bragging, but I don't know a better way to stress my opinion that a properly set up SxS in reasonably capable hands is in no way inferior to an O/U....not by a single target on the most strenuous par cour imaginable.