There’s two things that could get it acting right that I can think of: Replace the cylinder (expensive, may not work but might) Shim it i.e. find a washer with internal diameter of cylinder pin or smaller and rut it out to the right diameter, then file it down to the width that takes the play out ( couple issues with this, one it’ll increase the flash gap i.e. bigger halos, reduced velocity and increased leading, two potential annealing of the makeshift shim with the fram of the gun) Let us know how it goes