I bought my wife a H AND R pardner pump 20 guage. Has 21 inch barrel and is smooth bore and has a modified chocke. It is drilled and tapped for a scope. Has anybody ever used a smooth bore for deer hunting and if so whats the max range you think it would hit good and what ammo is best for this situation?

Here in Illinois we are limited to slug guns, so yep, thats what I shoot. I will shoot mine out to 75 yards, but never had to. I just use the standard winchester "rifled" slugs. I quotated rifle because as odd as it is, these are what goes through a smoothbore, sabot slugs go in a rifled barrel, go figure. Hope that helps and good hunting to you.