Gil;
That may not have been worded well, but didn't really know the exact correct terminology. What I was speaking of in the Inertia is uses inertia to switch from one barrel to the other, Thus if the first barrel should for some reason fail to fire a 2nd pull on the trigger will not fire the 2nd barrel.
What I was referring to as the Inertia Block is actually blocking the trigger pull with an inertia block. Some single triggers use this design. When the first barrel fires the recoil moves the inertia block over the trigger blade or elsewhere preventing the trigger from being pulled again until the block releases from spring pressure. This prevents the gun from doubling from the involuntary 2nd pull. In the event the first barrel doesn't fire the block, of course, doesn't move & as the trigger actually switches "Mechanically" a mere release & repull of the trigger will fire the 2nd barrel.
