Hardness Dimples on June 1942 manufactured Inland Receivers

[Hammer]

Painter777's favorite Old Threads showed a pic of Inland 1205 and I noticed it also had a round dimple impression on its left side receiver wall as I had seen on other June 1942 made Inland receivers. I posted about this on the Carbine Collectors Club a few months back when I found this round dimple impression on the left side of my Inland 270 Receiver and was curious what it was so I started asking around and looking at 3 and 4 digit Inlands and found this same impression on others that were made in June thru early August 1942. I saw these dimples (as I call them) on all of the 3 digit receivers pics I could find and on most of the 1000 series receivers, and on some of the 2000 series, but only on one in the 3000 series and it was SN 3546.

This round dimple is believed to be a hardness test. Its not the ping punch type markings seen on parts which are from a Rockwell hardness test. This larger round impression is believed to possibly be a Brinell Hardness test mark, which can measure the lower end of the hardness scale. Inland was doing this on its Receivers in its first month of production it seems and continued it sporadically into July and early August.

Some of these earliest receivers have just one dimple and others have up to 4 on them. They are on the different areas of only the the left side wall of the receiver.

Here's some pics from 3 digit and 1000, 2000, low-mid 3000 SN's.

Attachment 121604Attachment 121605Attachment 121606Attachment 121607

Information

Warning: This is a relatively older thread This discussion is older than 360 days. Some information contained in it may no longer be current.