I hunted with a Marlin .44 magnum thinking that it would be a superb short range deer hammer. I was sadly mistaken with that train of thought twice. The first was a spike horn buck taken at 40 yards using Win White box 240gr JSP. After the shot the buck bolted towrd a nearby swamp. He didn't quite make it but he made me go through some nasty thick stuff. When I took up his trail I was amazed that there was no spoor in the
snow indicating a hit. I took up his trail and didn't find any blood until I got about 25 yards in, then it was only pin head sized dropplets. I finally found him 100 yards latter, there was a exit wound however blood was only coming from the entrance wound.
Upon dressing him out I found the bullet centered the heart without expanding, which explains why he traveled so far. The next time I used the .44 magnum it was with a MAX load of H110 behind a Hornady 240gr XTP-HP. This time the shot was all of 30 yards. At the shot the buck took off through the woods headed for... you guessed it the thickest stuff available. I found him 150 yards later. With the poor performance that I experienced, coupled with more expensive reloading components, and the lack of affordable ammo or any ammo for that matter I sold that rifle immediately. Heck I haven't seen any .44 magnum here in more than a year.
I replaced the .44 with a NEF 20GA single shot shotgun and used it to harvest a nice whitetail doe. The terminal performance was light years ahead of what I experienced with the .44 magnum. I shot the doe from 40 yards away, she made a short stiff legged 20 yard jaunt and crashed, there was no shortage of spoor, or of a blood trail either. The terminal performance was no different than the deer I've taken with my 12GA. The Remington Slugger HP Slug wreaked havok on the internal organs, the trauma was immense. When you hit a game animal with a properly constructed slug things stop happening quick. Also don't be fooled by foster slugs they can be quite accurate from a smooth bore once you find the ammo it likes. How accurate can a rifled slug from a smoothbore be? Watch this video
http://www.youtube.com/watch?v=nNTyCcip-ks
Now I'm not advocating anyone should be shooting that far at game animals with a shotgun and rifled slugs. I posted that video to show that a rifled slug from a smoothbore can more accurate and dangerous than what most people think is possible. Given my experience having used both the .44 magnum from a rifle and a 20GA with slugs for deer, I'd pick the 20GA everyday and twice on Sunday.