This is a good read about one symptom of the problem. Another symptom would be it looks fine but blows up anyway without cracks showing up first.
One of the problems with the low number Springfield receivers is a lot of them were heat-treated well enough that they handled being fired. It's the few that could not handle it (or will not handle firing for much longer) that are the issue. As far as I know,
inspection of the grain structure by x-ray diffraction is the only non-destructive test you can do to find the large grains in "burnt" steel. I have never priced the service, but there are outfits that do it. It would be the choice if you had a low-numbered rifle that is collectible and wanted to see if you could safely shoot it.
Unfortunately, there are a number of people who will see the fact most low-numbered Springfields worked OK when they were in use as proof nothing was wrong with any of them. Pay particular attention to that blogger's takeaway #1. Shooters are often from Missouri in the figurative sense and will take the attitude that if they've never seen a thing, it doesn't exist. But you can't prove a negative, which is what they are claiming to have done with their past experience when they deny the existence of any issue at all. Their experience may prove the odds are low, but they can't prove it is zero until they've done it an infinite number of times. That's just the way the universe is wired.
