I have the same issue with the factory sights as 450 mentioned above and I am trying to find a lover base for the front sight to resolve this.

Any help with finding a supplier for these sights would be appreciated.

Another option for inertia triggers when the first barrel does not fire is to quickly thump the recoil pad with the heel of your right hand ( while keeping the muzzle pointed in a safe direction with your left hand on the fore end of the gun) reverse handing required for lefties of course. I have used this technique on occasion with my Franchi O/U trap gun and also tested that it works with the Fabarm Asper, it does require a fairly solid and sharp thump to approximate recoil to do this.