For what it is worth when I went to work for the Army Small Cal Lab in 70s I had access to most of the Army weapons engineers in the gov't so I conducted a informal survey in the lab.
The questions was: "If you were going to be put in someplace bad and you had your choice of one weapon to take what would it be?"
Every last guy said a 1903 or 03A3 Springfield. Why? they were the original Energizer Bunny and just kept on going and going and going.
03 actions were used on accuracy acceptance fixtures to test ammunition and they routinely saw 15,000 to 17,000 rounds on a barrel before it was "shot out". It would go into the shop and come out with a new Mann barrel on it and back to work.
In a long term survival situation the rifle least likely to fail will be the Springfield bolt gun. The Garand will inevitably go down when the cam on the bullet guide gets worn down and the clip will tend to jump ship about the sixth round. As well they tend to go out of time. The gas cyclinder will wear from the carbon which becomes an abrasive when it gets hardened after cooling down.
The acceptance accuracy on the Springfield was 3" at 100 yards, the Garand was five inches.
If you load the wrong propellant in the ammo for a Garand you will wreck the gas system by exceeding the port pressure. As well if you use the wrong propellant there will not be enough port pressure to drive the gas system.
There are not that many Garand mechanics left still working that really understand the system but the Springfield can be worked on by about any gunsmith that can run a lathe.
When a Garand barrel is gone you are down. If you choose your replacement Springfield barrel configuration properly you can cut off a barrel maybe four times and still keep on shooting. The purpose of cutting off the threads and rechambering is to keep good rifling at the chamber mouth which cannot be done with the Garand or M1A.
The Garand sights are in fact better than 03A3 sights but a properly reworked Springfield action can have outstanding iron sights, a good scope sight or both.
The Springfield will take a much wider range of loads and operate just fine where the Garand will not.
Last year the CMP got in a large number of Garand barrels and to order them you had to wait on line for like three hours. I ordered five of them as I figured there would in all liklihood never be another large batch of new Garand barrels to surface. Two went to a buddy and I kept three and had one built on a "issue" gun to shoot the Garand matches.
To my knowledge there are only about two shops capable of turning a Garand barrel that has the tooling to time the thread with the gas port. There are thousands of gunsmiths that can rebarrel a Springfield action.
Cleaning a Garand requires extreme care not to drag the cleaning rod on the muzzle which will destroy what little accuracy it has. Cleaning a Springfield from the action end is a much more user friendly situation both for the rifle and the owner.
As well the Springfield can be rebarreled for a number of calibers where the Garand cannot.
For a long term survival rifle the Springfield is the way to go. A gas operated rifle just won't hold up.
Distinguished Rifleman High Power & Smallbore Prone
President's Hundred (Rifle) US Palma Teams(2)
US Dewar Team (2),4 Man Natl.Champ Team SB Prone
Cert Test Dir. Sm Arms and Ammo,Aberdeen Pr Ground, Firefighter I, AC4HT