That third shot with a semi or pump is often a wasted shot,,,,,birds are usually too far away at the time of firing it. Having one rarely gets you more birds. When you know you've only got two shells to work with (O/U) you tend to make them count. That being said, I use a semi for waterfowl since my 'go to' O/U is only a 20 ga. which I've been using for upland bird hunting since 1980. I think I'll get buried with that gun!