PMC Plainfield-USGI parts compatibility problems

Thought I'd pass this along as many think most all parts are interchangeable between Plainfields and GI carbines.

Friend of a friend referred me to look over/repair a Plainfield carbine for him.
All PMC except having a real USGI C tip sling.

Original concern was FTF. Primers were being dented, but old ammo and had been reloaded. COAL'S WERE ALL OVER THE MAP.
fOUND THAT THE FIRING PIN SEEMED TO BE TRAVELING FAR ENOUGH BUT WAS BINDING heavily WITH THE EXTRACTOR AND EJECTOR.
The original PMC trigger housing shows a chipped inner edge on the left rail where the hammer would rest after being released.
Sometimes completely missing the trigger housings left rail stop and traveling forward falling partially between the trigger housing walls.
Causing it to hit the upper right rear side of the bolt but barely catching the rear of the firing pin.

Replaced that housing with a UEF t4 housing.
Put all the original PMC parts back in, except replaced the hammer and trigger pins with GI.
Found that the Hammer and trigger pins for the Plainfield housing need to stay with it. (different lengths than GI.)

After putting back in the original PMC hammer I could see too much side to side movement.
Dry firing it could cause it to walk sideways to the right and go beyond stop position, sometimes missing it's resting edge on the left rail of the USGI housing.
Compared the thickness of the PMC hammer to a GI and found the PMC to be much thinner.
Installed a GI hammer and all was well.

So after un-binding the ejector/extractor and firing pin and doing a complete thorough cleaning, it ran like a clock today.

I'm posting this 'Commercial Carbine Info Here' because of it's interchangeable parts with USGI.
Just something you might want to take note of.

Thank You,
Charlie-Painter777

Painter777--

PMC used M2 Hammers in a lot of their carbines. To take up the space where the "disconnector with spring plunger ?" went PMC placed a small washer to keep the M2 hammer walking on the hammer pin. You are quite right that most original GI parts are interchangeable with the PMC. Some minor fitting maybe required. I replaced quite a few shot-out GI barrels with new PMC barrels when carbines were legal in NJ.

--fjruple

Iver Johnson Gun Parts: Bob's Gun Shop

Here is a place to get those 2 pins if anyone needs to find them. I'm glad when i took mine apart i put them aside, but thougt i had lost them and read about those pins need go be from Iver, but i found them. I did have problems removing the ejector from the bolt. I replaced all parts in the bolt with GI parts. I still have and using the original aluminum trigger Housing, and the Hammer is a Underwoood. I guess i got lucky and have no problems with it and still dont. This Carbine has been taken care of and have to Thank my Father for teaching me at a young age to NEVER dry fire a Rifle or Pistol.