M1 carbine sight question

[Faulkner]

A replacement flip sight won't fix that problem.

Have you checked to see if the barrel to receiver index marks line up?

So just for grins, I pulled out one of my USGI carbines (an I.B.M.) and one of my two Iver Johnson's to take a look.

The top picture is the USGI I.B.M. and you can readily see the alignment index marks on the barrel and receiver that need to line up. They have to be very close for the barrel to index properly, otherwise you'll never be able to line up the front and rear sights.

The bottom picture is from my late model Iver Johnson M1 carbine, one of the last year production guns made in Jacksonville, Arkansas, around 1992ish. It's interesting to note it has NO index marks on either the receiver or the barrel. Not sure how they line them up. I've not shot this carbine in a few years but I note the rear sight is adjusted all the way over to the left which seems to indicates the barrel and receiver are probably not closely indexed.

Out of curiosity, I checked the other Iver Johnson M1 carbine I have in my vault (belongs to my brother). It doesn't have index marks either. Iver Johnson must have used some other method of lining up the barrel and receiver.

 

[LVSteve]

Perhaps Iver Johnson have some cunning arrangement involving the flats on the barrel and the receiver.

 

[JohnRippert]

Iver Johnson must have used some other method of lining up the barrel and receiver.

Or not, as the case seems to be.