It's not that the first ones made, ie low numbers were defective. They were single heat treated which made them hard, which is good. The problem came in because the heat treating was done "by eye". The armorer would heat the action to the appropriate red glow then process it. the problem was that on cloudy days the appropriate red glow appeared at a lower temperature and on bright days the action had to get significantly hotter for it to appear to have the same appropriate red glow. This difference in temperature resulted in over heating some of the actions, which led to the crystalline structure of the action being faulty. So basically, if the action was heat treated on a dismal day it will be a splendid action. If it was made on a bright sunny day, there's a chance that the steel has been burnt and would not hold the pounding of high pressure loads. Since all of these low number '03s are now over 100 years old, it's likely that if they were going to fail, they would have done so by now; but then I don't know that there's an effective way to check them other than firing a proof load in them, but that may just take it to the brink so that another standard pressure load would cause a failure. It seems that with all the modern equipment developed in the last several years that there should be a way to check the molecular structure of the metal without damaging its integrity. Or you could just admire the rifle for its history and not need to shoot it.