I calculated these number from Winchesters site for the 12ga 2.75 partition gold. Thought you may all be interested in the actual amount of lead needed to hit a running deer at usual ranges.
Yards Downrange / Deers Running Spped : Lead Required
25 / 5mph : 0.3ft, 15mph : 0.9ft, 30mph: 1.8ft
50 / 5mph : 0.6ft, 15mph : 1.8ft, 30mph : 3.6ft
75 / 5mph : 0.9ft, 15mph : 2.8ft, 30mph : 5.6ft
100 / 5mph : 1.3ft, 15mph : 3.8ft, 30mph : 7.6ft
125 / 5mph : 1.6ft, 15mph : 4.9ft, 30mph : 9.7ft
So to hit a deer running at 30 mph (we all no deer can go faster) at 75 yards you will have to lead it by 5.6 feet. Pretty far amount of lead, and this is with one of the hottest shotgun slugs out there, you can imagine what it would be for slugs that start off a good 400 fps less than the partition ( I am sure it would add a couple of feet the answer).
Not an easy shot to make consistantly.