Hardness Dimples on June 1942 manufactured Inland Receivers

[eb in oregon]

Attachment 121615

You can see four indentions on this Serial Number 34X receiver - two on the left front, one in the middle, and a larger one in the right rear. My SN 270 only has the one larger indention in the middle of the receiver's wall.

Checking multiple locations is common to insure the heat treating process is consistent. Again, once verified only spot checking is required. As manufacture gears up multiple tests are usually required. As it becomes apparent the process is consistent checking becomes more a random thing rather than a "check every one" thing. Time is money. Or a delay in getting guns to the troops. But that's merely an opinion.