first carbine unboxing

[painter777]

Get the mags tweaked asap.
Check any Trigger housing pin holes for excessive wear as stated by others.

Next I'd be looking for the longer type II mag catch / safety spring and plungers, using the later M stamped mag catch. This is what JackP is trying to point out.
Check bolt for burrs on the bottom front that push the casing forward. They can be lightly stoned.
Camming area on the hammer should be burr free and lightly greased.

Add: I like to lightly buff the feed ramp then a added drop of oil rubbed in with my finger.

** The longer Safety / Mag catch spring/plunger will push the later M stamped mag catches forward, which will raise the front of the mag.**

See TM9 1276 1947
http://www.90thidpg.us/Reference/Man...-1276_1947.pdf

Page 48 section J
27.) Check magazine catch spring plunger for retention on spring, wear,
and burs, and check spring for functioning, deformation, and set.
Free length of spring is 0.813 (approximately
7/8) inch. When assembled,
last coil of spring is contracted slightly and fits into groove in shank
of plunger for retention. Magazine catch (B7160470), and magazine
catch retainer plunger with safety plunger, assemblies (B7160472)
should be used. This is the catch that protrudes outward farther than
the old design, thereby providing greater engagement between the catch
and the nibs on the back of the magazine. It can be readily identified
by the letter "M " on the right-hand side.

Also on page 12:
(4) Chambering of cartridge. The bolt should chamber the cartridge
smoothly when released. If bullet ramp on receiver or barrel is rough,
or magazine loose so that it tips forward, the bullet may bind on ramp
or be deflected upward during chambering and strike the top of the
barrel and cause a stoppage.
(5) Position of cartridge in mouth of magazine. If magazine follower
does not position cartridge fully up against lips of magazine, the magazine spring may be weak or broken, or the tube or follower dented,
rusted, or burred, or the magazine incorrectly assembled. If dummy
cartridges are not available, depress follower to bottom of tube and
then allow it to rise. Inspect for smooth and positive functioning.

You'll figure it out soon enough. Good Luck,

[USGI]

Are you suggesting stock inletting might be loose enough the pin could slip out partway?

Yes, that's what was causing mine to jam. After it did it 2 or 3 times I noticed the slide got sort of hard to pull back, like something was trying to lock up. The empties were being extracted, but the misalignment caused by the out of place trigger pin was blocking the bolt from coming back far enough to strip the next round from the magazine - and instead got stuck in the groove at its base. At least that's how I was seeing it.

I made a longer pin out of a broken 1/8" drill bit. Went out a few days later and ran a full box of ammo through it without a problem. A poorly made aftermarket stock was the actual cause. If Charlie wants to donate a nice UEF stock, I saved the original pin! - Bob

[DaveHH]

That carbine looks to be almost brand new. Not a lot of use as the edges are all sharp and fresh looking. Amazing.

All of the jams are not caught by the extractor, either missing the bolt altogether or wedged at an angle hanging up inside the chamber. The bolt misses indicate that the bolt isn't going far enough to the rear. The ones that are not being held by the extractor indicate that there might be too little movement of the extractor as in spring hole is full of unburned powder, cotton scraps or hard grease. I had problems like this with my CMP NPM. I completely cleaned the extractor area and replaced the slide spring with a new genuine GI and the problems stopped.

If reloads, the bullet OAL can be too long and the tips drag on the front of the magazine on the inside and don't allow a round to rise up to be chambered.

[ssgross]

as in spring hole is full of unburned powder, cotton scraps or hard grease.

ruled that one before ever shooting.

** The longer Safety / Mag catch spring/plunger will push the later M stamped mag catches forward, which will raise the front of the mag.**

Thanks, Charlie. I have lots of things to try now - we are no where near giving up.

That carbine looks to be almost brand new. Not a lot of use as the edges are all sharp and fresh looking. Amazing.

It sure is amazing. I haven't reloaded for it...yet.

[ssgross]

Closing the loop on this. I think I solved the loose mag failure to feed problem.
On my African carbine (in another thread), the recoil plate was super loose - whole rifle jiggled in the stock. So I bought a type III for it - solved that problem. Just so happened the old recoil plate was an NPM type II. So I thought, what the hey, might as well try it in my failing-to-feed NPM, and replace the inland one it came with. It fit better than the one that was in it, and reduced the mag jiggles by half. So, I bought another NOS type III, fit is super tight, and now there is hardly any play in any of the magazines.
I think the type III recoil plate is pressing the top of the trigger housing forward, or better to say not letting it slip to the rear. You can see what I mean in this picture.


Only time at the range will confirm. If it starts to misfeed again, I have a new M-stamped mag catch to put in.