I think the idea behind the snap caps is two fold. One is to allow dry firing like you suggested and the other to help with malfunction drills, etc. I seriously doubt that your snap cap caused the pin breakage, it probably would have happened with a live round too. The only problems I've had with snap caps and rifles has been with the red plastic type with the brass base in 308. The rounds must not be the right spec as they get stuck in the chamber and are very hard to remove. This has happened with more than one gun, so I dont think it was just a tight chamber. The 30-06 cap I have is for both 30-06 and the 270. It doesnt have the "bullet" profile, just a shoulder. I've never had trouble with this one. Anymore, I've been using the A-Zoom caps, they seem to last longer and the "primer" doesnt get stuck in the case after using it awhile.