So I have had some issues with my Garand.
One issue, as it cycles it is not picking up another round from the clip. I have changed out the gas plug to allow for modern ammo to be shot. So this happens when I am using surplus military ammo. So is it pressure problem?

The other and major issue.
Back story: So i purchased several hundred rounds of foreign military surplus ammo. There have been a lot of duds. The primers do not fire off. So I have separated the lots that dont fire. Pulled the bullets, collect the powder. I took an average powder charge out of the lot and reloaded the bullet and powder into once fired new production brass. I only reloaded 16 rounds to try out to make sure they work. As pictured below, I have had several necks break off during firing. Only realized it when a round would not load completely. Ejected the round to find a broken neck on the unfired cartridge. This happened in about four rounds. Each of the rounds were RP brass. I do put a light crimp on the load, but will stop doing that. Can anyone give me an idea of why this brass would be doing this?

Holy cow, I wouldn't be shooting that ammunition anymore. How do the case heads look? Is there damaged from the extraction process too? Next question is what type of gas plug did you use? Is it an adjustable one?

I would check my throat area if that’s new never fired brass and it pulling necks off?

These are reloads. The case heads are fine. Sometimes they dent in, but from where and how they land. The gas plug is not adjustable. I would have to find the package it came in.

Its not new brass. Its once fired brass. I was saying its newer modern 30-06 brass as compared with the surplus ammo i have. It has only happened to the RP brass though.

Trying to follow your sequence of events...you say you changed your gas regulation to suit modern ammo, but then are basically firing ammo that was loaded originally as military stuff only in different brass. If that's correct I'd say you need to change your gas port back to the original setting to fire this ammo.

I am no Garand expert, but it seems logical.

What plug did you install? Is it hollow where the original one was not? Issue might be short stroking due to the added room for gas with the new plug. powder charge might need to increase a bit. These should reduce gas pressure, not increase.

I have seen older Brass have neck separation. Had some older Norma in 303 Brit that did the same thing. Pulled all the bullets powder and primers. Cleaned annealed and then reloaded. Had several do this with my own proven loads. Not sure why. I scrapped all the brass. Never happened with any of my other loads. I would try new factory ammo or switch to different brass to see if the problem goes away.

As far as the feeding issue
First make sure you grease the follower tracks in the receiver.
If that doesn't work get a new op rod spring.

As for the issue w the brass, no clue.

I think its a issue with commercial modern ammo. I WOULD NOT run modern commercial ammo thru my M1 Garand. I load it with the service rifle loads in the Hornady reloading book.

Modern ammo, even with an adjustable plug, can BEND your op rod, or operate the gun WAY TOO FAST. Result is your ripping the brass out of the chamber before the pressure can drop. To me, you don't have the gas port adjusted correctly and its slamming your oprod back at a velocity thats faster than intended. So fast, its ripping the brass, ejecting so fast that the bolt hits the rear of the receiver then slams home before the magazine can push the next round up.

To be specific, its not modern ammo. Just newer brass. When I broke down the dud surplus ammo. I just reused the components into newer brass. As far as the gas plug, it is the hollow style, but I am not aware that it is adjustable, unless that requires to screw it in or out more. As I have read the hollow plug allowed for the higher pressures with modern ammo so the system wasn't over gassed and pressurized, or at least that was their selling point. I think I will change out the plug back to the original and see if that corrects the feeding issue. I will probably stop using the RP brass as it is the only brand of brass doing this.

That's ugly! I'd maybe make a post on the CMP forums.

After your clarification I'll go out on the limb with a saw and propose that your feeding issue is due to your alteration or modification of the gas system, and the case necks being pulled off is just due to a batch of bad brass and is coincidental.

Call Port Clinton. They have seen everything.

I had a Garand I bought there when I lived in Cleveland. It was zeroing with the rear aperture to the left and the front sight to the right.

I took the rifle back and told them the guy said something about a steel rod and a mini sledge.

He then said I can trade it out for another rifle. I chose the second. The replacement shot true.

That was 20ish years ago when 30-06 was still 18 cents a round and Garands were less than $500.

I have never seen brass separate like in your pictures. I have a few 1000 rounds through my Garands and have seen a few 1000 more at the ranges I used to shoot at.