I have this soule made in ukraine I believe.
It has a tiny amount of play,maybe .010-.015" when upright, for and aft, this would be apparent at the top of the staff which is a schuetzen short range length. My MVA snaps in solidly.
What amount of elevation error is possible with this movement? 
I guess the right way you guys do it is to reset the sight after each shot? or do you just leave it as it is?  thanks

I have a PU Soule that has a small amount of side play when in the upright position. I see no way to adjust the slack out.

Reset?  Not sure what you guys mean by reset. 

Sounds like the nose of your spring is not contacting the bottom of the detent in the staff when the sight is upright.
Mine snaps up very tight. The side play bugs me.

Just checked my sight again. It has play for and aft and side to side play. I really like the sight but will most likely replace it with a Walker style. Might try to eliminate the slack. Maybe...

I use two Soules, on CPA,s one a Mike Stevens mid range new in 1993 over 20,000 38/55 cartridges through the gun. The sprung detent holds it tight when aiming and firing. Last few years the  Staff moves forward a bit and stays forward on recoil. After every shot I pull it back. Same routine required on a Unertl scope, I run the  return spring on my scopes loose. 

Other Soule is  MVA Schuetzen short staff New in 1999. The guns has a lower round count and 32/40, lighter recoil. Does not need to be returned to vertical after a shot. There’s less wear on  the sight and lighter recoil makes the difference.

Often see shooters with stiff bill hats that hit the tang sight on recoil. Some return it vertical others don’t. Sight at an angle the arpeture is not square, sight picture is fuzzy. Best wear a short soft bill hat using a tang sight with a large disk 

Side play is bad I would replace the sight. 

Boats