Our lease is being overtaken by hogs. I'm wanting to get a big bore barrell for my Encore and have been considering the 45-70, 450 Marlin, 460 and the 500 S&W. What would you suggest. Most shots would like be 50 yards or less.

Any of those would do the job and then some. If it was me, I would opt for the .460, just because I want one OTT will make you one http://www.ottllc.com/ All you have to do is make two dumby rounds with your dies and he will make the chamber to your dies.

I have a 375 JDJ...

Won't make much difference if its a 270 or a 450 marlin. All will do the job on hogs.

At this point its whatever one you want.

Buy the 45-70 and you will be able to shoot factory ammo that is loaded to low pressure or factory ammo loaded hot. One load that is great is the Winchester Supreme with a 300 gr. Partition. I've used this load out of a borrowed guide gun to take several feral hogs.