Originally posted by AgentL Thanks for the recommendations, folks! I believe the more moderate telephoto of the 55-300 would be better for his needs. He's not a photographer, at all, so while he knows what photos he wants to get, he doesn't know how they're made. He will have to find out what he likes.
What's a reasonable larger aperture option in the same basic range?
The 300 f/4 is another option. You can get an FA 300 f/4.5 for cheaper than the DA version but it is not very usable below f/5.6 in my opinion.
A better lens for wildlife is either the 150-450 for Pentax or a 150-600 for other brands. But those lenses are much heavier, and much more expensive.
Here's my opinion: if the 70-300 doesn't work for him for some reason, and because he is not heavily into photography, then get him a used superzoom bridge like the P950. The reason I say that is that beyond the 70-300 range, options are much heavier, more expensive, and require more work to actually push those options to their limits and get your money's worth out of it.