Can't really use the slugs for much, so I'd think that you are better off sticking with birdshot. They are pretty much useless unless you are within about 15 yards. What would be your intended target?

The FPS and slug weight turn out having less terminal effectiveness than my .40 S&W. I'd rather use my .40 than a .410 slug.

Not legal for deer, as I believe I read 20 gauge minimum for deer, bear, cougar. 12 gauge minimum for elk.