Find some goey swamp mud...open the action of a Garand, fill it full of mud...open the action of an Enfield...fill it full of mud...then clean it out...which one ya gonna back in action faster?
Heck, I don't know about the M1 (it's internal magazine is it's most vulnerable feature) but I know that "test" would be no problem for my M14 rifle. All I'd have to do it take out the mag and watch the mud drip out of the reciever, the problem is more or less solved.
Your rifle may be the best bolt action rifle, but ultimate SHTF gun? Not a chance! For one thing ammo is corrosive, difficult to find (if you have to leave your stash) and the bore is not chrome lined! Corrosive ammo + unchromed bore = big long term problems. Hardly the SHTF type resistence I'd want.
I can think of several firearms that would be better but, like another said, it depends on your enviorment. If you are going to be in an area where you'll NEED to be able to make long range shots (past 300 meters) then that limits the options some. However, if a shot is going to be that far out, you should be avoiding trouble anyway. And where I live, a shot that is past 200-300 yards, it really hard to find. Unless you're facing down a highway or something similar.
Anyway, if you just HAVE to make those 300+ meter shots than I recommend the M14.
1. It is more accurate than the enfield, the .308 ammo can be found anywhere, from gas stations to wal-marts, heck even our own armed forces still use the round.
2. It is VERY reliable. Someone who was an X marine claimed that in all his firearms experience, the M14 was the 2nd most reliable gun, beaten only by the AK. Nice chrome bore helps add to this, don't need to clean it as often. + It's self regulating gas system.
3. Thirdly, it has a high capacity, which may not make a difference if you are shooting at 500 yards, but it will make a difference if you are engaging targets at under 200 yards, espessially multiple targets.
4. It is the best of all worlds in that it can be loaded by a mag change, by stripper clips, or by hand feeding the rounds into the follower from the top. So, if you loose all your spare mags, you still have a 20 shot rifle in your hands! There is no other battle rifle that can do all of these three loading methods (as someone before mentioned, enfield doesn't function well in mag changes, as rounds fall out).
5. Nice light weight, and it is the lightest weight battle rifle there is when in a synthetic stock. Even lighter still if we are talking Bush or the new SOCOM.
Now, as I mentioned earlier, if you don't HAVE to have a rifle that can make 300+ yard shots, your options open up even more. Two other rifles that are better than the enfield in the under 300 yard option are the SKS and AK47 types. There are other good options as well.