I recently paid for a pack of o-rings from a member here to practice dry fire because ejecting snap caps to rack the slide was getting annoying.
Out of pure curiousity, I took my SP-01 to the range and loaded the pistol with the o-ring. To my surprise, it shot my 124gr plated RN reload with Winchester WSP and 5.6gr Alliant Power Pistol with no problem.
I understand the o-ring and snap caps soften the blow, but was hoping to hear some thoughts of it's overall effectiveness in preventing firing pin related damage.