In 2003, Browning and Winchester introduced the 243 WSSM. For the same reason one should try not to say anything bad about another’s dog, I always try to find something positive to say about a cartridge but sometimes that just is not possible, this is one of those times. I have looked at it every way it can be looked at. I have discussed it with others who have more related experience and know far more than I do. Nothing helped. The very best comment I got was from my lifelong friend, Roy Runnestrand (whose father mentored my interest in firearms), “It looks cool!” It has the possible distinction of being, perhaps, one of the two or three worst factory designs ever standardized for a modern cartridge. Owing to the extremely short neck and relatively large capacity, it requires use of a chrome-lined bore to give acceptable barrel life. Because it is extremely hard to apply chrome lining to a bore without significantly compromising accuracy, manufacturers that cared about accuracy refused to chamber it. Refer to the discussion on the 223 WSSM. <em>The Japanese evidently solved the accuracy problem with chrome-lined bores in the 1940s or earlier. While this seems to be a very well-kept secret, they built phenomenally accurate 7.7 Arisaka Sniper rifles. These used chrome-lined bores.</em> <em>My late friend, Craig Coburn, owned one that would shoot Norma factory loads into a tiny ragged hole at 100 yards until he ran out of ammo and did so every time he tested it! So, it would seem chrome-lining a bore without significantly compromising accuracy is possible; likely very expensive to do, but possible.</em> The 243 WSSM will not do anything the 6mm Remington will not do and it has far less than half the barrel life of the 6mm Remington. About the most positive things I can say about this round are: first, by shortening the body to increase neck length and using an elliptical shoulder, the case made a fine basis for excellent 22- and 24-caliber wildcats using the patented SMc design features; second, it offers a modest performance advantage over the 243 Winchester. As with any high-performance round, barrel heating is a significant concern. Allowing plenty of time for barrel cooling can significantly increase barrel life. Conversely, overheating the barrel by rapid firing can render a barrel uselessly inaccurate after surprisingly few shots, even if it does have a chrome-lined bore. For a big game hunter this is not much of a concern; for a varmint hunter it certainly can be. As with the 223 WSSM, while I would like to find an encouraging word for anyone owning such a rifle, that is rather hard to do. My best advice, avoid barrel heating like you would avoid the plague and use the gun sparingly. A final note, this round and the related 223 WSSM and 25 WSSM all directly infringe parametric SMc design patents. Amazingly, by being so poorly engineered in all other ways, these rounds do so without providing any advantages the SMc concept offers — improved performance, increased barrel life, reduced barrel heating, reduced felt recoil, and improved accuracy! Design details matter. For this reason, this insult to the patent owners is less offensive than it otherwise might be.