Inherited Dad's M1 Carbine, an Irwin Pedersen

[tenOC]

Doubtful that sources call it a line. It's a machining step but it's easier to tell someone to look for a line. Think I've got approx 9 Grand Rapids triggers but only one is close to not having a notch. Surely several of those would be from later production. The diff probably just comes from human operators.

[Allard J2]

Understood, thank you. Saw a really rough Winchester M1 Carbine today in local gun shop. Was actually surprised they had one, but no sling, beat up stock, about a foot long stamped series of numbers on the side of the stock, filled in with white paint. $1895.

[USGI]

Could it be that Saginaw S'G' was gradually taking steps to eliminate the--imperfections for lack of a better word--that had given the Irwin Pedersen group their quality control issues and gotten their contract taken away? If it has the line and not the notch, maybe there are others the same, after S'G' corrected/eliminated whatever tooling difference was causing the senseless notch? That's a WAG, of course.

Your WAG about tooling and setup problems at IP are well documented in WarBaby! After the takeover by Saginaw, it was found that many of the methods and jigs used for machining operations of the various parts relied on locator holes, etc. that resulted in inaccuracy and wasted production time. Saginaw implemented changes to correct this. An example was the tooling locator hole toward the rear, on the side of the trigger housing, which became smaller and nearly disappeared by the end of production. I'll attach a picture showing your IP housing along with the one from my 1.82 S'G' for comparison. Those GB auction pictures were really interesting! - Picture #5 shows a flip safety that has been over-stamped. Also interesting is the "green" IP flat bolt. - Bob

[tenOC]

beat up stock, about a foot long stamped series of numbers on the side of the stock, filled in with white paint. $1895.

That's typically an Israeli feature, the serial number.
On the trigger milling I was picturing it out of the housing. With it in place you can't really see that it's a verticle line. Sorry for the confusion.

[tenOC]

Vertical.

[Allard J2]

Sounds like War Baby is a book I should own! Thank you for all the comments and tips.

[Maniac]

Could it be that Saginaw S'G' was gradually taking steps to eliminate the--imperfections for lack of a better word--that had given the Irwin Pedersen group their quality control issues and gotten their contract taken away? If it has the line and not the notch, maybe there are others the same, after S'G' corrected/eliminated whatever tooling difference was causing the senseless notch?

FWIW, the trigger on my 1.87 S'G' (9-43 UEF barrel) has the notch.

[Bruce McAskill]

Very hard to find an IP let alone one such as this one.

[new2brass]

The OPs Trigger is consistent with what was made at the Grand Rapids Plant.
The Grand Rapids plant machined things differently. The mark on back of the trigger was actually a hole similar to the holes on the trigger housing made at Grand Rapids. This was to locate the trigger for machining operations. Later that material was eliminated. Think of the waste.
These triggers have been seen with deep grooves to no groove. It may be due to moving the hole or maybe the trigger is thinner from more material being removed. The finishing process to the back of trigger may have been done by hand causing the variation.

[m1a1fan]

Nice IP finish. Is it a UW Barrel date of 1 2 or 3 of 43? Leaf marked RP? IPN front sight with a number possibly on the side? Is there a mark on the receiver bottom forward of the rear trigger housing lug? It may look like a fat man, pine needle, house with a cross or something else. The book says original IP's are 4K plus. Think that number is, IMHO, conservative. Even middle of nowhere auctions bring out the dealers. If other collectors know of one at auction, and it's original it would go waaaaaayyyy higher. Add more for more IP parts. See lots of crap pretending to be original these days. 4.5k for a repark mixmaster in that GB link. Yikes!