I had a couple of my recently acquired Pre'64's apart for a check over and cleanup.

I've never seen this before and I've had at least 15 of these apart.

It's a stainless steel insert rivetted into the front of the mag box.

This is a 1958 standard in 270.

Someone check the "Rule" book and tell us if this is factory.

Rembo it isn't "factory".

I have read of some older smith's doing that to keep cartridges from flying forward under recoil and battering bullet noses against the inside of the magazine box.

I have collected M/70's for 40yrs., never seen anything like that. Purpose is as stated above, whether it is really needed or not who knows.

I bet the old Gunsmith that did that fix is long gone, looks like a weld not a rivet. Clean job. very best Winpoor

I was googleing pre-64 Mod 70's as I am about to get my first one and I'm trying to learn as much as I can about them.

On You Tube of all places, there was a video on this very thing. Apparently this was "fairly" common on some Pre 70's

Do you have a link to that video?
Did they say it was a factory part?.... it doesn't look like a "one off" with it's multiple bends. Don't think anyone would go through all the trouble for a one time part.