I had one that was 99% outside but had serious pitting. Replacement barrels are rare and expensive. I spoke with JES and he agreed to rebore it to create a 9x55 Swiss (really .357). He did a 3 groove and it works perfectly. I "hogged out" some 358 Winchester dies to leave the neck sizing and seating parts intact. Works perfectly. The Swiss case has more capacity than the 358 Winchester and, as we know, from Swiss websites, many K-31s have been rebarreled to 50 K+ (243/308/25-06 etc) cartridges with no ill effects. My interest is not in hot-rodding it, rather cast boolits. Initial results w/220 gr Lee PCed and 250 gr Speer were good. Now have it scoped and waiting for range to reopen.