Got mine installed just before muzzle loader season and checked zero. Shot good but I only shot enough to make sure my scope was still ON. Our season ends in another week and then I plan to bolt a bigger scope and see what she'll do. Did not get any blow-back, but that had not been a problem anyway. Biggest advantage so far....those hornet cases are sure a lot easier to handle with my old, cold, arthritic, fumbling fingers than the 209's. GOOD SHOOTIN', Walt :-D :-D :-D :-D