My first couple range trips with my recently acquired 1943 M1 only had a couple hiccups where the rifle just didn’t pick up the next round - bang then click- nothing in the chamber.

When I ordered the new rear sight cover spring I decided to order a brand new oprod spring. The new spring is about 1/4” longer than the original spring. The first range trip with the new spring was yesterday and it failed to feed a few times with Greek HXP M2 ball ammo - only 3-4 times out of close to 50 rounds.

Today I decided to shoot reloads -
LC brass, 168 Gr Nosler HPBT, Winchester WLR primers, and 46.5 Grains of IMR4895 powder. COAL was 3.285” The groups were AWESOME but it NEVER ONCE fed the new round into the chamber. It ejected fine, but didn’t feed.

Every single shot, I had to manually charge the handle. Even the clip wouldn’t fly out after the last round. After 16 rounds I called it quits.
Of course I didn’t have any Greek ammo with me to try today.

I took the rifle apart, there’s a little wear to the finish on the right side of the oprod, I do not know if this is normal or a sign of a problem. I’ll post a pic.
The “tilt” test is fine - no oprod spring or trigger group in the rifle (just barreled receiver and stock) and the bolt and oprod slide both directions freely
The gas tube didn’t look terrible, not like it was plugged but it could use a cleaning.

What do I need to look for now ?
Could the new oprod spring just be too stiff and need to break in ?
Is it normal for the receiver to overhang the stock like mine does ? ( see pic )

Edit - on the second pic you can see how with just finger pressure you can easily make the oprod hit one side of the handguard but it doesn’t go the opposite direction and hit the handguard on the other side so easily

Attached File
Attached File
Attached File
Attached File

Your rifle looks really dry.  Grease not to much and also follow the recommendations from the guys here.

Try it again with your old op rod spring. The new one might be too stiff.
Also, get some grease on/in the op rod guide.

I may be overlooking it but who made your replacement op-rod spring?

As for the stock that is not normal overhang.  It should have a little bit of a "porch".

Before the pics I wiped grease off the oprod to show the wear on there to see if it were a concern. She was plenty lubed up as well as the oprod spring when I was at the range.

I’ll try the new spring with the Greek ammo plus the old spring again with greek and now reloads.

Shit.

Can that have an effect on function in any way ? Like the allignment of the oprod in the handguard ?

Well,

I have the original Oprod spring back in the rifle, shes properly greased. I also cleaned and inspected the gas tube and cleaned the end of the oprod. Tomorrow we will see if she feeds properly with both Greek HXP ammo and reloads.

With the replacement spring I was getting 100% failure to feed.

Right now I’m at the range with the original spring.

Greek ammo - first two clips ran flawlessly while firing standing.
While resting on sandbags the next 2-3 clips had one failure to pick up per clip, after the first shot.

Reloads - ran fine so far but the clip didn’t eject on the last round.

Who made and sold the replacement spring?

I'd like to know so that I don't waste my time and money when I buy one.

Shouldn't need hardly any grease.  It really should be able to run dry.

what does the gas piston mic at?

I’ll mic the gas piston as soon as possible. It’ll take a few days.

I’m sorry I was asked previously who the spring came from and that was a website I think is called www.ammogarand.com

I took the oprod out of my 1953 Springfield and put it into this 1943 Springfield - I didnt touch a single other thing.

I ran 3 clips of Greek HXP ammo through it without a single failure to feed.

So it appears the Oprod the 1943 came with is out of spec, or possibly bent ??

The piston on the fucky Oprod measures .0525"

I can see a bend / warp / bow in the oprod... 5 or so inches from the piston

I was in a hurry to swap oprods and didn’t measure the piston on the 1953 oprod, once I swap them back out I’ll measure that piston and compare for bends.
Perhaps the 1953 rifles piston is wider and that’s all she needed to fit the gas cylinder properly.

This seems to the place to send them to for replacing the piston. I’m pumped to have some results finally

http://www.columbusmachine.com/oprod.htm

I’ve seen tools to measure the gas cylinders but do not have any of them

Thank you for all your advice and help so far

So my oprod that does NOT work in the 1943 is uncut and guages at 0.525” at the piston.

The oprod that DOES WORK is cut, and measures at 0.529-0.530”

I’m going to contact Columbus to have them work this one over

Ordered ! Thanks !