which constriction?

[knightrider]

21 inch 20gauge barrel do i need a 555 or 570 shooting hevi #6

[sugarray]

Determine what you want your 10" numbers to be, then decide.  With the 6s you are already going to be lower than a lot of what you see here, b/c many are shooting 7s.

[dawei]

21 inch 20gauge barrel do i need a 555 or 570 shooting hevi #6

What brand of 20ga gun do you have please?

[knightrider]

21 inch 20gauge barrel do i need a 555 or 570 shooting hevi #6

What brand of 20ga gun do you have please?

oops that may help. its for my sons h@r pardner 20 with 21 in barrel, ive already polished and put sights on it and gave it a wicked camo job,know i need some help on where to start with choke diameter. dont want real tight but a good even 20in pattern at 35-40

[surehuntsalot]

just my .02,but  I would go with something in the .570-.575 range

[dawei]

I concur w/surehuntsalot and recommend .570". Will you be using HTL or Pb loads?

[knightrider]

I concur w/surehuntsalot and recommend .570". Will you be using HTL or Pb loads?

hevi 6 

[WyoHunter]

I shoot a .573 in my Beretta but I shoot Hevi 7's.