I would imagine you will get many responses as this has been killed many times over. I can almost bet that over 95% of the answers is that it is dangerous and should never be used on a DGR as it is an accident waiting to happen, but a failed primer is almost as possible also and they rarely fail to my knowledge. The facts that will be quoted is they are small and can let the rim slip by and jam the rifle. This is of course possible,but so is primer failure. They are in most case no smaller than the Remington extractors and they don't often fail to extract so size is not the prime factor. For the rim to slip over the ejector the ejector has to be depressed and stick and of course could happen if the gun is not kept clean. I have owned several rimless chamberings in double rifles,both O/U and SxS and have yet to have a failure of any kind with any of them. They have been made for many years by all the major players and I don't think they would if they were not satisfactory. Ruger No1's have for all practical purposes the same type extraction in as much as the extractor is not attached to a 'bolt'. They rarely fail to the best of my knowledge. As to the pressure part of the rimless equation,that probably has a valid question mark attached to it. Break action guns are not as strong in their lockup as bolt action guns and as a result don't handle high pressures as well. How much and how it affects the action is subject for almost as much controversy as the ejectors. My reasoning is if the Manufacturer does not believe the liability is so great that he continues to produce the guns I will continue to use them. I can almost gaurantee you this is the MINORITY view.