I tend to agree with Nato. It's more dependant on your ability than the slug's is. If you're not scoping the gun, I personally wouldn't shoot past 100. Your iron sights are going to cover almost half a deer if you go further than that. If you scope your shotgun, the slugs will be lethal still at 125 or a little more before they start falling off fast. At least that's my experience with my Winchester model 1300 and regular ole Winchester Super X Slugs. By the way, I LOVE the price on those! 10 bucks for 15 at Wally World, gotta love it!