I recently installed a muzzle brake from Thunder Beast Arms which was supplied with a peel style timing washer. In theory this should have been a simple job however the washer appears to have been stamped rather than cleanly cut and this caused issues.
As i progressively removed more layers a burr developed (due to the punching) on both the outer circumference and inner hole preventing a clean lockup. In addition the burr made it increasingly more difficult to remove single layers and it started to come away in chunks.