Springfield 1940 M1 receiver variation

There were a few receivers from the 37K serial number range to the 43K serial number range
with an extra wide guide rib. To date there are about a dozen known examples and most of
them have had the 7th round correction. As to the reason for this variation, it is not known
but suspect it would relate to the seventh round problem.

Both a normal receiver sn 41159 and an extra wide rib receiver sn 42593 are shown together,
both are original receivers without any modification to the guideAttachment 51643Attachment 51644Attachment 51645Attachment 51646 ribs

Very Nice!!

Thank you