with todays loads and choke tube options barrel legnth comes down to pretty much personal prefrence in the end. "turkey guns" in the past has 30+" barrels and usually full choked barrels.

alot of turkey guns today have 20-24" barrels and high tech choke tubes in them with advanced shells that throw better patterns at 50yds then the old "turkey guns" threw at 30yds.

me, i prefer short n sweet for my turkey gun. manuvers better, less barrel to be spotted moving, less chances of it hitting trees and limbs etc, lighter, and still throws an awesome pattern and will rock a turkey at 50+ with hevi shot. but for my upland bird hunting, i like 28-30+" barrels. they swing better IMO..and give you a longer sight plane...

but, last week i took my 870 with a 21" barrel grouse hunting. i knew id be in thick thickk cover and covering MILES. i didnt wanna carry the heavy, long mossberg...5 shells fired...2 dead grouse. 1 was a 1 shot kill..the misses were my fault..

just personal preferance...barrel legnth also adds velocity upto a certain point..think its like 20fps per inch of barrel out to 28+ or something. so my 21" is shooting the same shell 140fps slower than a 28" barrel...but, i havent had any animal tell me my shot was moving to slowly...

some will still argue that the longer the barrel the better the pattern...but in todays world, i just dont see it...shells and chokes have came a long way and were at a point where the gun patterns well enough to kill game at extreme ranges for a shotgun, but the pellets dont retain their energy well enough to kill the animal...yep, even the stump barrels...