First off I would like to say that for my first 7 years of huntingI was not fortunate enough to hunt in the northern hunting zones of New York state, therefore requiring me to use a shotgun to harvest deer. For the first five of those years I used regular old rifled slugs (Winchester super x) I took them to the range and sighted them in at 114 yds.and 15 shots punched out a hole a bit smaller than a tennis ball. Since then I have used winchester's partition golds. In the first 7 years I harvested 11 deer, and in thefollowing 4 years I harvested 7 more deer. (All with slugs).And I can honestly say, that out of all 18 of those deer I have never seen one of them run more than 55 yards and only 1 out of the 18 deer required more than one slug to kill it.

However, in the last 3 years I have been fortunate to be able to hunt northern zone. I have used my 30-06 all 3 years and have killed 4 deer with that gun. I could not believehow much more effective the rifle was at ( STOPPING) the deer immediately. 3 of those deer didn't even move after they were hit. and the 4th deer only went about 7 steps and collapsed.

I also would like to add that out of the total22deer that I have shot with both shotgun and rifle, only one of the 22 deer where shot at over 100 yds. And I didn't use my rifle either. I used winchester supreme partition golds and they smacked a nice 5 pt. at 143 yds. He only went about 26 paces before he died.

I am a firm believer in shot placementover velocities and foot pounds of energy. Only an idiot would claim that a shotgun would not kill a whitetail effectively. Because I belive they have stood the test of time. And with that being said, the "so - called" weaker cartridges like the 243, 250 savage,30-30, 38-40, 38-55and 257 roberts have also proved thier rankings over time on their ability to harvestwhitetail deer. (just to name a few.)
You dont need a cannon or anti tank rocket to kill a whitetail deer.( especially inside 100 yards) You just need to hit em where it counts.

I believe that both a slug gun and a rifle will kill deer effectively within their own abilities. If you stay within a good range with the slug, you should be able to kill any whitetail out there (provided you hit em right)

However, In my personal opinion, and from what I have personally experienced,I would choose a good rifle over the shotgun as well. I truly believe they(can be) more accurate than the slug. (just because a gun is only as accurate as its shooter) And for # 2 I know thata good rifle brings the energy. I dont want to track or drag a deer any further than I have to. If I shoot and I see the deer fall immediately (its fine with me)

If your freind will be hunting within 100 yards (he could use the shotgun) if he wants. But I really think he would appreciate the effectiveness and light recoils of a good 30-30, 243, or even a 7mm-08. He doesn't need a magnum for inside 100 yards and his shoulder shouldn't have to pay the price for it either.

I hope your freind get what he wants and is comfortable shooting with. (That is the most important thing) ButI would discuss some nice mild rifles with him, I think he will thank you in the long run.