if it is for slugs and slugs alone, i would recommend a savage, 210(12ga) or 220(20ga) bolt action, a NEF ultra slugger(single shot break), or a TC encore with 28" rifled barrel (single shot break....and probably pushing a tad over $600). those are about the currently made most accurate FACTORY setups with out spending a fortune. 870's with a well fitted, rifled cantilever barrel will shoot very good as well. I have shot most every slug on the market, and it is most always true that the slower twist barrels (such as a hastings 1:34) best shoot the close to bore size sabots (lightfields, buckhammers, brenneks, list goes on....) at medium velocities no more than 1700fps or so. Where as the ultra fast (1800fps+) glittery box, pretty ballistic tip smaller cal. sabots (core lokt ultras, XP3's SST's) most always stabalize best with a fast twist tube (1:28). do note that if you can stabalize the faster sleeker slugs, indeed shoot them, the usually have more energy retained after 100 yds. or so.

Hope this helps....good luck