My friend also has his best results in his 3" 870..28" barrel with the 3" WIn HV #6's.I'd say stick with it if you are shooting 45yds or less.Go with 5's up to 50yds or so,and 4's to 55yds.If you were shooting a 3.5" I'd add 5yds to each of those distances,b/c there is 1/4 oz more shot in them.Hope I helped.